feat(accounts): implement user accounts, sessions, and dashboards

Introduce Stage 4 features to support multi-user accounts, cookie-based web sessions, and personal dashboards.

Changes include:
- Adding `/register` to bootstrap the first admin account and `/login`/`/logout` for session management.
- Creating a personal dashboard (`/app`) to display owned boxes, storage usage, and upload history.
- Implementing admin user management (`/admin/users`) for generating invite links and managing user states.
- Updating the bbolt database schema to store users, sessions, invites, and collections.
- Adding `golang.org/x/crypto` for password hashing and introducing unit tests for account handlers.

README.md

@@ -20,7 +20,12 @@ Background jobs are enabled with `WARPBOX_JOBS_ENABLED=true`. Individual jobs ca
 `WARPBOX_CLEANUP_ENABLED` and `WARPBOX_THUMBNAIL_ENABLED`, and their schedules are configured with
 `WARPBOX_CLEANUP_EVERY` and `WARPBOX_THUMBNAIL_EVERY`.
 
-The basic admin console is available at `/admin`. Set `WARPBOX_ADMIN_TOKEN` and use that value to sign in.
+On a fresh data directory, visit `/register` to create the first account. That first user becomes
+the instance admin and normal registration closes after bootstrap. Admins can create copyable invite
+links from `/admin/users`.
+
+The env admin token still exists as emergency fallback access. Set `WARPBOX_ADMIN_TOKEN` and use it
+at `/admin/login` if you need to recover access without a user session.
 
 For one-off Go commands, run them from the backend module:
 
@@ -97,6 +102,23 @@ curl -F sharex=@./screenshot.png \
 The upload endpoint accepts multipart fields named `file` and `sharex`. ShareX users can start
 from `examples/sharex/warpbox-anonymous.sxcu`; update `RequestURL` to match your instance URL.
 
+## Stage 4 Accounts + Personal Boxes
+
+- `/register` bootstraps the first admin account only when no users exist.
+- `/login` and `/logout` provide cookie-based web sessions.
+- `/app` is the personal dashboard for logged-in users, showing owned boxes, storage usage, upload
+  history, and flat collections. Uploading still happens from the homepage.
+- `/admin/users` lets admins create invite links, disable/reactivate users, and generate reset links.
+- Logged-in browser uploads from `/` still use `POST /api/v1/upload`, but the resulting box is
+  stored with owner and optional collection metadata.
+- Admin users are exempt from the global max upload size on the homepage upload flow. Future
+  per-user quotas should apply to this same upload path rather than creating a second uploader.
+- Anonymous uploads, ShareX uploads, unlisted public box links, password protection, expiry, delete
+  tokens, thumbnails, and cleanup continue to work as before.
+
+Email delivery is intentionally deferred. Invite and reset links are copyable today; future SMTP
+support will power public forgot-password and optional email delivery.
+
 ## Runtime Data
 
 Warpbox keeps local runtime data under the configured data directory:
@@ -104,6 +126,7 @@ Warpbox keeps local runtime data under the configured data directory:
 - `data/files/{box_id}/@each@{file_id}.ext` - uploaded file contents.
 - `data/files/{box_id}/@thumb@{file_id}.jpg` - generated previews where available.
 - `data/db/warpbox.bbolt` - bbolt metadata database for boxes and file records.
+- `data/db/warpbox.bbolt` also stores users, sessions, invites, and collections.
 - `data/logs/{YYYY-MM-DD}.log` - JSONL logs, one event per line.
 
 ## Static Asset Policy

backend/go.mod

@@ -4,7 +4,8 @@ go 1.26
 
 require (
 	go.etcd.io/bbolt v1.4.3
+	golang.org/x/crypto v0.33.0
 	golang.org/x/image v0.41.0
 )
 
-require golang.org/x/sys v0.29.0 // indirect
+require golang.org/x/sys v0.30.0 // indirect

backend/go.sum

@@ -6,11 +6,13 @@ github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOf
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 go.etcd.io/bbolt v1.4.3 h1:dEadXpI6G79deX5prL3QRNP6JB8UxVkqo4UPnHaNXJo=
 go.etcd.io/bbolt v1.4.3/go.mod h1:tKQlpPaYCVFctUIgFKFnAlvbmB3tpy1vkTnDWohtc0E=
+golang.org/x/crypto v0.33.0 h1:IOBPskki6Lysi0lo9qQvbxiQ+FvsCC/YWOecCHAixus=
+golang.org/x/crypto v0.33.0/go.mod h1:bVdXmD7IV/4GdElGPozy6U7lWdRXA4qyRVGJV57uQ5M=
 golang.org/x/image v0.41.0 h1:8wS72eGJMJaBxK6okTzd4WaXumUlTVlb753MlsSvTCo=
 golang.org/x/image v0.41.0/go.mod h1:uIc348UZMSvS5Z65CVZ7iDPaNobNFEPeJ4kbqTOszmA=
 golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
 golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
-golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

backend/libs/handlers/accounts_test.go

@@ -0,0 +1,165 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"warpbox.dev/backend/libs/services"
+)
+
+func TestLoggedInUploadStoresOwnerAndAnonymousUploadDoesNot(t *testing.T) {
+	app, cleanup := newTestApp(t)
+	defer cleanup()
+
+	user, err := app.authService.CreateBootstrapUser("daniel", "daniel@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	_, token, err := app.authService.Login("daniel@example.test", "password123")
+	if err != nil {
+		t.Fatalf("Login returned error: %v", err)
+	}
+
+	request := multipartUploadRequest(t, "/api/v1/upload", "file", "owned.txt", "owned")
+	request.Header.Set("Accept", "application/json")
+	request.AddCookie(&http.Cookie{Name: userSessionCookieName, Value: token})
+	response := httptest.NewRecorder()
+	app.Upload(response, request)
+	if response.Code != http.StatusCreated {
+		t.Fatalf("owned upload status = %d, body = %s", response.Code, response.Body.String())
+	}
+	var ownedPayload services.UploadResult
+	if err := json.Unmarshal(response.Body.Bytes(), &ownedPayload); err != nil {
+		t.Fatalf("json.Unmarshal owned returned error: %v", err)
+	}
+	ownedBox, err := app.uploadService.GetBox(ownedPayload.BoxID)
+	if err != nil {
+		t.Fatalf("GetBox owned returned error: %v", err)
+	}
+	if ownedBox.OwnerID != user.ID {
+		t.Fatalf("owned OwnerID = %q, want %q", ownedBox.OwnerID, user.ID)
+	}
+
+	owned := uploadThroughApp(t, app)
+	anonymous, err := app.uploadService.GetBox(owned.BoxID)
+	if err != nil {
+		t.Fatalf("GetBox anonymous returned error: %v", err)
+	}
+	if anonymous.OwnerID != "" {
+		t.Fatalf("anonymous OwnerID = %q, want empty", anonymous.OwnerID)
+	}
+
+	boxes, err := app.uploadService.ListBoxes(0)
+	if err != nil {
+		t.Fatalf("ListBoxes returned error: %v", err)
+	}
+	foundOwned := false
+	for _, box := range boxes {
+		if box.OwnerID == user.ID {
+			foundOwned = true
+		}
+	}
+	if !foundOwned {
+		t.Fatalf("logged-in upload did not store owner id %q", user.ID)
+	}
+}
+
+func TestInviteHandlerCreatesUserAndMarksInviteUsed(t *testing.T) {
+	app, cleanup := newTestApp(t)
+	defer cleanup()
+
+	admin, err := app.authService.CreateBootstrapUser("admin", "admin@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	invite, err := app.authService.CreateInvite("friend@example.test", services.UserRoleUser, admin.ID, 0)
+	if err != nil {
+		t.Fatalf("CreateInvite returned error: %v", err)
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "/invite/"+invite.Token, strings.NewReader("username=friend&password=password123"))
+	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	request.SetPathValue("token", invite.Token)
+	response := httptest.NewRecorder()
+	app.InvitePost(response, request)
+	if response.Code != http.StatusSeeOther {
+		t.Fatalf("InvitePost status = %d, body = %s", response.Code, response.Body.String())
+	}
+	if _, err := app.authService.AcceptInvite(invite.Token, "friend", "password123"); err == nil {
+		t.Fatalf("invite token remained reusable")
+	}
+}
+
+func TestNonOwnerCannotManageOwnedBox(t *testing.T) {
+	app, cleanup := newTestApp(t)
+	defer cleanup()
+
+	owner, err := app.authService.CreateBootstrapUser("owner", "owner@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	invite, err := app.authService.CreateInvite("other@example.test", services.UserRoleUser, owner.ID, 0)
+	if err != nil {
+		t.Fatalf("CreateInvite returned error: %v", err)
+	}
+	other, err := app.authService.AcceptInvite(invite.Token, "other", "password123")
+	if err != nil {
+		t.Fatalf("AcceptInvite returned error: %v", err)
+	}
+
+	result := createOwnedBoxThroughApp(t, app, owner.ID)
+	if err := app.uploadService.RenameOwnedBox(result.BoxID, other.ID, "stolen"); err == nil {
+		t.Fatalf("RenameOwnedBox allowed non-owner")
+	}
+}
+
+func TestAdminUploadBypassesMaxUploadSize(t *testing.T) {
+	app, cleanup := newTestApp(t)
+	defer cleanup()
+
+	_, err := app.authService.CreateBootstrapUser("admin", "admin@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	_, token, err := app.authService.Login("admin@example.test", "password123")
+	if err != nil {
+		t.Fatalf("Login returned error: %v", err)
+	}
+
+	request := multipartUploadRequest(t, "/api/v1/upload", "file", "large.txt", strings.Repeat("x", int(app.uploadService.MaxUploadSize())+1))
+	request.Header.Set("Accept", "application/json")
+	request.AddCookie(&http.Cookie{Name: userSessionCookieName, Value: token})
+	response := httptest.NewRecorder()
+	app.Upload(response, request)
+	if response.Code != http.StatusCreated {
+		t.Fatalf("admin upload status = %d, body = %s", response.Code, response.Body.String())
+	}
+}
+
+func createOwnedBoxThroughApp(t *testing.T, app *App, userID string) services.UploadResult {
+	t.Helper()
+	user, err := app.authService.UserByID(userID)
+	if err != nil {
+		t.Fatalf("UserByID returned error: %v", err)
+	}
+	_, token, err := app.authService.Login(user.Email, "password123")
+	if err != nil {
+		t.Fatalf("Login returned error: %v", err)
+	}
+	request := multipartUploadRequest(t, "/api/v1/upload", "file", "owned.txt", "owned")
+	request.Header.Set("Accept", "application/json")
+	request.AddCookie(&http.Cookie{Name: userSessionCookieName, Value: token})
+	response := httptest.NewRecorder()
+	app.Upload(response, request)
+	if response.Code != http.StatusCreated {
+		t.Fatalf("upload status = %d, body = %s", response.Code, response.Body.String())
+	}
+	var payload services.UploadResult
+	if err := json.Unmarshal(response.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("json.Unmarshal returned error: %v", err)
+	}
+	return payload
+}

backend/libs/handlers/admin.go

@@ -4,6 +4,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"net/http"
+	"net/url"
 	"time"
 
 	"warpbox.dev/backend/libs/services"
@@ -15,11 +16,14 @@ const adminCookieName = "warpbox_admin"
 type adminPageData struct {
 	Stats         services.AdminStats
 	Boxes         []adminBoxView
+	Users         []adminUserView
+	LastInviteURL string
 	Error         string
 }
 
 type adminBoxView struct {
 	ID             string
+	Owner          string
 	CreatedAt      string
 	ExpiresAt      string
 	FileCount      int
@@ -30,6 +34,15 @@ type adminBoxView struct {
 	Expired        bool
 }
 
+type adminUserView struct {
+	ID        string
+	Username  string
+	Email     string
+	Role      string
+	Status    string
+	CreatedAt string
+}
+
 func (a *App) AdminLogin(w http.ResponseWriter, r *http.Request) {
 	if a.isAdmin(r) {
 		http.Redirect(w, r, "/admin", http.StatusSeeOther)
@@ -63,6 +76,7 @@ func (a *App) AdminLoginPost(w http.ResponseWriter, r *http.Request) {
 }
 
 func (a *App) AdminLogout(w http.ResponseWriter, r *http.Request) {
+	a.clearUserSessionCookie(w)
 	http.SetCookie(w, &http.Cookie{
 		Name:     adminCookieName,
 		Value:    "",
@@ -93,6 +107,7 @@ func (a *App) AdminDashboard(w http.ResponseWriter, r *http.Request) {
 	a.renderer.Render(w, http.StatusOK, "admin.html", web.PageData{
 		Title:       "Admin overview",
 		Description: "Warpbox admin overview.",
+		CurrentUser: a.currentPublicUser(r),
 		Data: adminPageData{
 			Stats: stats,
 			Boxes: boxes,
@@ -119,6 +134,7 @@ func (a *App) AdminFiles(w http.ResponseWriter, r *http.Request) {
 	a.renderer.Render(w, http.StatusOK, "admin.html", web.PageData{
 		Title:       "Admin files",
 		Description: "Manage Warpbox uploads.",
+		CurrentUser: a.currentPublicUser(r),
 		Data: adminPageData{
 			Stats: stats,
 			Boxes: boxes,
@@ -126,6 +142,86 @@ func (a *App) AdminFiles(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+func (a *App) AdminUsers(w http.ResponseWriter, r *http.Request) {
+	if !a.requireAdmin(w, r) {
+		return
+	}
+	stats, err := a.uploadService.AdminStats()
+	if err != nil {
+		http.Error(w, "unable to load admin stats", http.StatusInternalServerError)
+		return
+	}
+	users, err := a.authService.ListUsers()
+	if err != nil {
+		http.Error(w, "unable to load users", http.StatusInternalServerError)
+		return
+	}
+	rows := make([]adminUserView, 0, len(users))
+	for _, user := range users {
+		rows = append(rows, adminUserView{
+			ID:        user.ID,
+			Username:  user.Username,
+			Email:     user.Email,
+			Role:      user.Role,
+			Status:    user.Status,
+			CreatedAt: user.CreatedAt.Format("Jan 2 15:04"),
+		})
+	}
+	a.renderer.Render(w, http.StatusOK, "admin_users.html", web.PageData{
+		Title:       "Admin users",
+		Description: "Manage Warpbox users and invites.",
+		CurrentUser: a.currentPublicUser(r),
+		Data: adminPageData{
+			Stats:         stats,
+			Users:         rows,
+			LastInviteURL: r.URL.Query().Get("invite"),
+		},
+	})
+}
+
+func (a *App) AdminCreateInvite(w http.ResponseWriter, r *http.Request) {
+	admin, ok := a.requireAdminUser(w, r)
+	if !ok {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		http.Redirect(w, r, "/admin/users", http.StatusSeeOther)
+		return
+	}
+	result, err := a.authService.CreateInvite(r.FormValue("email"), r.FormValue("role"), admin.ID, 7*24*time.Hour)
+	if err != nil {
+		http.Redirect(w, r, "/admin/users", http.StatusSeeOther)
+		return
+	}
+	a.logger.Info("invite created", "source", "admin", "severity", "user_activity", "code", 2404, "admin_id", admin.ID)
+	http.Redirect(w, r, "/admin/users?invite="+url.QueryEscape(result.URL), http.StatusSeeOther)
+}
+
+func (a *App) AdminDisableUser(w http.ResponseWriter, r *http.Request) {
+	if !a.requireAdmin(w, r) {
+		return
+	}
+	disabled := r.URL.Query().Get("disabled") != "false"
+	if err := a.authService.DisableUser(r.PathValue("userID"), disabled); err != nil {
+		http.Error(w, "unable to update user", http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/admin/users", http.StatusSeeOther)
+}
+
+func (a *App) AdminResetUser(w http.ResponseWriter, r *http.Request) {
+	admin, ok := a.requireAdminUser(w, r)
+	if !ok {
+		return
+	}
+	result, err := a.authService.CreatePasswordResetInvite(r.PathValue("userID"), admin.ID)
+	if err != nil {
+		http.Error(w, "unable to create reset link", http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/admin/users?invite="+url.QueryEscape(result.URL), http.StatusSeeOther)
+}
+
 func (a *App) AdminDeleteBox(w http.ResponseWriter, r *http.Request) {
 	if !a.requireAdmin(w, r) {
 		return
@@ -185,8 +281,17 @@ func (a *App) adminBoxes(limit int) ([]adminBoxView, error) {
 
 	rows := make([]adminBoxView, 0, len(boxes))
 	for _, box := range boxes {
+		owner := "Anonymous"
+		if box.OwnerID != "" {
+			if user, err := a.authService.UserByID(box.OwnerID); err == nil {
+				owner = user.Email
+			} else {
+				owner = "User"
+			}
+		}
 		rows = append(rows, adminBoxView{
 			ID:             box.ID,
+			Owner:          owner,
 			CreatedAt:      box.CreatedAt.Format("Jan 2 15:04"),
 			ExpiresAt:      box.ExpiresAt.Format("Jan 2 15:04"),
 			FileCount:      box.FileCount,
@@ -209,6 +314,9 @@ func (a *App) requireAdmin(w http.ResponseWriter, r *http.Request) bool {
 }
 
 func (a *App) isAdmin(r *http.Request) bool {
+	if user, ok := a.currentUser(r); ok && user.Role == services.UserRoleAdmin {
+		return true
+	}
 	if a.cfg.AdminToken == "" {
 		return false
 	}
@@ -219,6 +327,25 @@ func (a *App) isAdmin(r *http.Request) bool {
 	return cookie.Value == adminCookieValue(a.cfg.AdminToken)
 }
 
+func (a *App) requireAdminUser(w http.ResponseWriter, r *http.Request) (services.User, bool) {
+	user, ok := a.currentUser(r)
+	if ok && user.Role == services.UserRoleAdmin {
+		return user, true
+	}
+	if a.cfg.AdminToken != "" && a.isAdmin(r) {
+		return services.User{ID: "env-admin", Role: services.UserRoleAdmin, Status: services.UserStatusActive}, true
+	}
+	http.Redirect(w, r, "/login?next="+r.URL.Path, http.StatusSeeOther)
+	return services.User{}, false
+}
+
+func (a *App) currentPublicUser(r *http.Request) any {
+	if user, ok := a.currentUser(r); ok {
+		return a.authService.PublicUser(user)
+	}
+	return nil
+}
+
 func adminCookieValue(token string) string {
 	sum := sha256.Sum256([]byte("warpbox-admin:" + token))
 	return hex.EncodeToString(sum[:])

backend/libs/handlers/app.go

@@ -14,25 +14,45 @@ type App struct {
 	logger        *slog.Logger
 	renderer      *web.Renderer
 	uploadService *services.UploadService
+	authService   *services.AuthService
 }
 
-func NewApp(cfg config.Config, logger *slog.Logger, renderer *web.Renderer, uploadService *services.UploadService) *App {
+func NewApp(cfg config.Config, logger *slog.Logger, renderer *web.Renderer, uploadService *services.UploadService, authService *services.AuthService) *App {
 	return &App{
 		cfg:           cfg,
 		logger:        logger,
 		renderer:      renderer,
 		uploadService: uploadService,
+		authService:   authService,
 	}
 }
 
 func (a *App) RegisterRoutes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /", a.Home)
 	mux.HandleFunc("GET /api", a.APIDocs)
+	mux.HandleFunc("GET /register", a.Register)
+	mux.HandleFunc("POST /register", a.RegisterPost)
+	mux.HandleFunc("GET /login", a.Login)
+	mux.HandleFunc("POST /login", a.LoginPost)
+	mux.HandleFunc("POST /logout", a.Logout)
+	mux.HandleFunc("GET /invite/{token}", a.Invite)
+	mux.HandleFunc("POST /invite/{token}", a.InvitePost)
+	mux.HandleFunc("GET /app", a.Dashboard)
+	mux.HandleFunc("POST /app/collections", a.CreateCollection)
+	mux.HandleFunc("POST /app/boxes/{boxID}/rename", a.RenameUserBox)
+	mux.HandleFunc("POST /app/boxes/{boxID}/move", a.MoveUserBox)
+	mux.HandleFunc("POST /app/boxes/{boxID}/delete", a.DeleteUserBox)
+	mux.HandleFunc("GET /account/settings", a.AccountSettings)
+	mux.HandleFunc("POST /account/password", a.ChangePassword)
 	mux.HandleFunc("GET /admin/login", a.AdminLogin)
 	mux.HandleFunc("POST /admin/login", a.AdminLoginPost)
 	mux.HandleFunc("POST /admin/logout", a.AdminLogout)
 	mux.HandleFunc("GET /admin", a.AdminDashboard)
 	mux.HandleFunc("GET /admin/files", a.AdminFiles)
+	mux.HandleFunc("GET /admin/users", a.AdminUsers)
+	mux.HandleFunc("POST /admin/invites", a.AdminCreateInvite)
+	mux.HandleFunc("POST /admin/users/{userID}/disable", a.AdminDisableUser)
+	mux.HandleFunc("POST /admin/users/{userID}/reset", a.AdminResetUser)
 	mux.HandleFunc("GET /admin/boxes/{boxID}/view", a.AdminViewBox)
 	mux.HandleFunc("POST /admin/boxes/{boxID}/delete", a.AdminDeleteBox)
 	mux.HandleFunc("GET /d/{boxID}", a.DownloadPage)

backend/libs/handlers/auth.go

@@ -0,0 +1,211 @@
+package handlers
+
+import (
+	"net/http"
+	"time"
+
+	"warpbox.dev/backend/libs/services"
+	"warpbox.dev/backend/libs/web"
+)
+
+const userSessionCookieName = "warpbox_session"
+
+type authPageData struct {
+	Mode       string
+	Token      string
+	Email      string
+	IsReset    bool
+	Error      string
+	ReturnPath string
+}
+
+func (a *App) Register(w http.ResponseWriter, r *http.Request) {
+	available, err := a.authService.BootstrapAvailable()
+	if err != nil {
+		http.Error(w, "unable to check registration", http.StatusInternalServerError)
+		return
+	}
+	if !available {
+		http.Redirect(w, r, "/login", http.StatusSeeOther)
+		return
+	}
+	a.renderAuth(w, http.StatusOK, authPageData{Mode: "register"})
+}
+
+func (a *App) RegisterPost(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		a.renderAuth(w, http.StatusBadRequest, authPageData{Mode: "register", Error: "Unable to read form."})
+		return
+	}
+	user, err := a.authService.CreateBootstrapUser(r.FormValue("username"), r.FormValue("email"), r.FormValue("password"))
+	if err != nil {
+		a.renderAuth(w, http.StatusBadRequest, authPageData{Mode: "register", Error: err.Error()})
+		return
+	}
+	a.logger.Info("first admin created", "source", "auth", "severity", "user_activity", "code", 2401, "user_id", user.ID)
+	a.loginAndRedirect(w, r, user.Email, r.FormValue("password"), "/app")
+}
+
+func (a *App) Login(w http.ResponseWriter, r *http.Request) {
+	if _, ok := a.currentUser(r); ok {
+		http.Redirect(w, r, "/app", http.StatusSeeOther)
+		return
+	}
+	a.renderAuth(w, http.StatusOK, authPageData{Mode: "login", ReturnPath: r.URL.Query().Get("next")})
+}
+
+func (a *App) LoginPost(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		a.renderAuth(w, http.StatusBadRequest, authPageData{Mode: "login", Error: "Unable to read form."})
+		return
+	}
+	next := r.FormValue("next")
+	if next == "" {
+		next = "/app"
+	}
+	user, token, err := a.authService.Login(r.FormValue("email"), r.FormValue("password"))
+	if err != nil {
+		a.logger.Warn("login failed", "source", "auth", "severity", "warn", "code", 4401, "email", r.FormValue("email"))
+		a.renderAuth(w, http.StatusUnauthorized, authPageData{Mode: "login", Error: "Invalid email or password.", ReturnPath: next})
+		return
+	}
+	a.setUserSessionCookie(w, r, token)
+	a.logger.Info("user login", "source", "auth", "severity", "user_activity", "code", 2402, "user_id", user.ID)
+	http.Redirect(w, r, safeReturnPath(next), http.StatusSeeOther)
+}
+
+func (a *App) Logout(w http.ResponseWriter, r *http.Request) {
+	if cookie, err := r.Cookie(userSessionCookieName); err == nil {
+		_ = a.authService.Logout(cookie.Value)
+	}
+	a.clearUserSessionCookie(w)
+	http.Redirect(w, r, "/", http.StatusSeeOther)
+}
+
+func (a *App) Invite(w http.ResponseWriter, r *http.Request) {
+	invite, err := a.authService.InviteByToken(r.PathValue("token"))
+	if err != nil || invite.UsedAt != nil || time.Now().UTC().After(invite.ExpiresAt) {
+		a.renderAuth(w, http.StatusNotFound, authPageData{Mode: "invite", Error: "This invite is invalid or expired."})
+		return
+	}
+	a.renderAuth(w, http.StatusOK, authPageData{Mode: "invite", Token: r.PathValue("token"), Email: invite.Email, IsReset: invite.UserID != ""})
+}
+
+func (a *App) InvitePost(w http.ResponseWriter, r *http.Request) {
+	token := r.PathValue("token")
+	invite, err := a.authService.InviteByToken(token)
+	if err != nil {
+		a.renderAuth(w, http.StatusNotFound, authPageData{Mode: "invite", Error: "This invite is invalid or expired."})
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		a.renderAuth(w, http.StatusBadRequest, authPageData{Mode: "invite", Token: token, Email: invite.Email, IsReset: invite.UserID != "", Error: "Unable to read form."})
+		return
+	}
+	user, err := a.authService.AcceptInvite(token, r.FormValue("username"), r.FormValue("password"))
+	if err != nil {
+		a.renderAuth(w, http.StatusBadRequest, authPageData{Mode: "invite", Token: token, Email: invite.Email, IsReset: invite.UserID != "", Error: err.Error()})
+		return
+	}
+	a.logger.Info("invite accepted", "source", "auth", "severity", "user_activity", "code", 2403, "user_id", user.ID)
+	a.loginAndRedirect(w, r, user.Email, r.FormValue("password"), "/app")
+}
+
+func (a *App) AccountSettings(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	a.renderer.Render(w, http.StatusOK, "account.html", web.PageData{
+		Title:       "Account settings",
+		Description: "Manage your Warpbox account.",
+		CurrentUser: a.authService.PublicUser(user),
+		Data:        user,
+	})
+}
+
+func (a *App) ChangePassword(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		http.Redirect(w, r, "/account/settings", http.StatusSeeOther)
+		return
+	}
+	if !services.VerifyPasswordHash(user.PasswordHash, r.FormValue("current_password")) {
+		http.Redirect(w, r, "/account/settings", http.StatusSeeOther)
+		return
+	}
+	if err := a.authService.SetPassword(user.ID, r.FormValue("new_password")); err != nil {
+		http.Redirect(w, r, "/account/settings", http.StatusSeeOther)
+		return
+	}
+	http.Redirect(w, r, "/account/settings", http.StatusSeeOther)
+}
+
+func (a *App) renderAuth(w http.ResponseWriter, status int, data authPageData) {
+	a.renderer.Render(w, status, "auth.html", web.PageData{
+		Title:       "Account",
+		Description: "Sign in to Warpbox.",
+		Data:        data,
+	})
+}
+
+func (a *App) loginAndRedirect(w http.ResponseWriter, r *http.Request, email, password, path string) {
+	_, token, err := a.authService.Login(email, password)
+	if err != nil {
+		http.Redirect(w, r, "/login", http.StatusSeeOther)
+		return
+	}
+	a.setUserSessionCookie(w, r, token)
+	http.Redirect(w, r, path, http.StatusSeeOther)
+}
+
+func (a *App) currentUser(r *http.Request) (services.User, bool) {
+	cookie, err := r.Cookie(userSessionCookieName)
+	if err != nil {
+		return services.User{}, false
+	}
+	user, _, err := a.authService.UserForSession(cookie.Value)
+	return user, err == nil
+}
+
+func (a *App) requireUser(w http.ResponseWriter, r *http.Request) (services.User, bool) {
+	user, ok := a.currentUser(r)
+	if ok {
+		return user, true
+	}
+	http.Redirect(w, r, "/login?next="+r.URL.Path, http.StatusSeeOther)
+	return services.User{}, false
+}
+
+func (a *App) setUserSessionCookie(w http.ResponseWriter, r *http.Request, token string) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     userSessionCookieName,
+		Value:    token,
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		Secure:   r.TLS != nil,
+		Expires:  time.Now().Add(30 * 24 * time.Hour),
+	})
+}
+
+func (a *App) clearUserSessionCookie(w http.ResponseWriter) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     userSessionCookieName,
+		Value:    "",
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		MaxAge:   -1,
+	})
+}
+
+func safeReturnPath(path string) string {
+	if path == "" || path[0] != '/' || len(path) > 1 && path[1] == '/' {
+		return "/app"
+	}
+	return path
+}

backend/libs/handlers/dashboard.go

@@ -0,0 +1,179 @@
+package handlers
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+
+	"warpbox.dev/backend/libs/helpers"
+	"warpbox.dev/backend/libs/services"
+	"warpbox.dev/backend/libs/web"
+)
+
+type dashboardData struct {
+	User          services.PublicUser
+	Collections   []collectionView
+	Boxes         []userBoxView
+	StorageUsed   string
+	MaxUploadSize string
+	Selected      string
+	LastInviteURL string
+}
+
+type collectionView struct {
+	ID   string
+	Name string
+}
+
+type userBoxView struct {
+	ID             string
+	Title          string
+	CollectionID   string
+	CollectionName string
+	FileCount      int
+	Size           string
+	CreatedAt      string
+	ExpiresAt      string
+	URL            string
+}
+
+func (a *App) Dashboard(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	collections, err := a.authService.ListCollections(user.ID)
+	if err != nil {
+		http.Error(w, "unable to load collections", http.StatusInternalServerError)
+		return
+	}
+	collectionNames := map[string]string{}
+	collectionViews := make([]collectionView, 0, len(collections))
+	for _, collection := range collections {
+		collectionNames[collection.ID] = collection.Name
+		collectionViews = append(collectionViews, collectionView{ID: collection.ID, Name: collection.Name})
+	}
+	boxes, err := a.uploadService.UserBoxes(user.ID, collectionNames)
+	if err != nil {
+		http.Error(w, "unable to load boxes", http.StatusInternalServerError)
+		return
+	}
+	storageUsed, err := a.uploadService.UserStorageUsed(user.ID)
+	if err != nil {
+		http.Error(w, "unable to load storage usage", http.StatusInternalServerError)
+		return
+	}
+
+	selected := r.URL.Query().Get("collection")
+	boxViews := make([]userBoxView, 0, len(boxes))
+	for _, row := range boxes {
+		if selected != "" && row.Box.CollectionID != selected {
+			continue
+		}
+		title := row.Box.Title
+		if title == "" {
+			title = fmt.Sprintf("%d file upload", len(row.Box.Files))
+		}
+		boxViews = append(boxViews, userBoxView{
+			ID:             row.Box.ID,
+			Title:          title,
+			CollectionID:   row.Box.CollectionID,
+			CollectionName: row.CollectionName,
+			FileCount:      len(row.Box.Files),
+			Size:           row.TotalSizeLabel,
+			CreatedAt:      row.Box.CreatedAt.Format("Jan 2 15:04"),
+			ExpiresAt:      row.Box.ExpiresAt.Format("Jan 2 15:04"),
+			URL:            "/d/" + row.Box.ID,
+		})
+	}
+
+	a.renderer.Render(w, http.StatusOK, "dashboard.html", web.PageData{
+		Title:       "My files",
+		Description: "Your Warpbox personal file space.",
+		CurrentUser: a.authService.PublicUser(user),
+		Data: dashboardData{
+			User:          a.authService.PublicUser(user),
+			Collections:   collectionViews,
+			Boxes:         boxViews,
+			StorageUsed:   helpers.FormatBytes(storageUsed),
+			MaxUploadSize: a.uploadService.MaxUploadSizeLabel(),
+			Selected:      selected,
+		},
+	})
+}
+
+func (a *App) CreateCollection(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		http.Redirect(w, r, "/app", http.StatusSeeOther)
+		return
+	}
+	if _, err := a.authService.CreateCollection(user.ID, r.FormValue("name")); err != nil {
+		a.logger.Warn("collection create failed", "source", "user_activity", "severity", "warn", "code", 4410, "user_id", user.ID, "error", err.Error())
+	}
+	http.Redirect(w, r, "/app", http.StatusSeeOther)
+}
+
+func (a *App) RenameUserBox(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		http.Redirect(w, r, "/app", http.StatusSeeOther)
+		return
+	}
+	if err := a.uploadService.RenameOwnedBox(r.PathValue("boxID"), user.ID, r.FormValue("title")); err != nil {
+		a.handleUserBoxError(w, r, err)
+		return
+	}
+	http.Redirect(w, r, "/app", http.StatusSeeOther)
+}
+
+func (a *App) MoveUserBox(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		http.Redirect(w, r, "/app", http.StatusSeeOther)
+		return
+	}
+	collectionID := r.FormValue("collection_id")
+	if !a.authService.CollectionOwnedBy(collectionID, user.ID) {
+		http.Error(w, "collection not found", http.StatusForbidden)
+		return
+	}
+	if err := a.uploadService.MoveOwnedBox(r.PathValue("boxID"), user.ID, collectionID); err != nil {
+		a.handleUserBoxError(w, r, err)
+		return
+	}
+	http.Redirect(w, r, "/app", http.StatusSeeOther)
+}
+
+func (a *App) DeleteUserBox(w http.ResponseWriter, r *http.Request) {
+	user, ok := a.requireUser(w, r)
+	if !ok {
+		return
+	}
+	if err := a.uploadService.DeleteOwnedBox(r.PathValue("boxID"), user.ID); err != nil {
+		a.handleUserBoxError(w, r, err)
+		return
+	}
+	http.Redirect(w, r, "/app", http.StatusSeeOther)
+}
+
+func (a *App) handleUserBoxError(w http.ResponseWriter, r *http.Request, err error) {
+	if os.IsPermission(err) {
+		http.Error(w, "not allowed", http.StatusForbidden)
+		return
+	}
+	if os.IsNotExist(err) {
+		http.NotFound(w, r)
+		return
+	}
+	http.Error(w, "unable to update box", http.StatusInternalServerError)
+}

backend/libs/handlers/pages.go

@@ -3,19 +3,38 @@ package handlers
 import (
 	"net/http"
 
+	"warpbox.dev/backend/libs/services"
 	"warpbox.dev/backend/libs/web"
 )
 
 type homeData struct {
 	MaxUploadSize string
+	Collections   []collectionView
+	IsAdmin       bool
 }
 
 func (a *App) Home(w http.ResponseWriter, r *http.Request) {
+	currentUser := a.currentPublicUser(r)
+	var collections []collectionView
+	var isAdmin bool
+	if user, ok := a.currentUser(r); ok {
+		isAdmin = user.Role == services.UserRoleAdmin
+		userCollections, err := a.authService.ListCollections(user.ID)
+		if err == nil {
+			collections = make([]collectionView, 0, len(userCollections))
+			for _, collection := range userCollections {
+				collections = append(collections, collectionView{ID: collection.ID, Name: collection.Name})
+			}
+		}
+	}
 	a.renderer.Render(w, http.StatusOK, "home.html", web.PageData{
 		Title:       "Upload your files",
 		Description: "Upload and share files through a self-hosted Warpbox instance.",
+		CurrentUser: currentUser,
 		Data: homeData{
 			MaxUploadSize: a.uploadService.MaxUploadSizeLabel(),
+			Collections:   collections,
+			IsAdmin:       isAdmin,
 		},
 	})
 }

backend/libs/handlers/upload.go

@@ -14,18 +14,39 @@ import (
 )
 
 func (a *App) Upload(w http.ResponseWriter, r *http.Request) {
+	user, loggedIn := a.currentUser(r)
+	isAdminUpload := loggedIn && user.Role == services.UserRoleAdmin
+	if !isAdminUpload {
 		r.Body = http.MaxBytesReader(w, r.Body, a.uploadService.MaxUploadSize()*8)
-	if err := r.ParseMultipartForm(a.uploadService.MaxUploadSize() * 8); err != nil {
+	}
+	parseLimit := a.uploadService.MaxUploadSize() * 8
+	if isAdminUpload {
+		parseLimit = 32 << 20
+	}
+	if err := r.ParseMultipartForm(parseLimit); err != nil {
 		helpers.WriteJSONError(w, http.StatusBadRequest, "upload form could not be read")
 		return
 	}
 
 	files := uploadFiles(r)
+	var ownerID string
+	var collectionID string
+	if loggedIn {
+		ownerID = user.ID
+		collectionID = r.FormValue("collection_id")
+		if !a.authService.CollectionOwnedBy(collectionID, user.ID) {
+			helpers.WriteJSONError(w, http.StatusForbidden, "collection not found")
+			return
+		}
+	}
 	result, err := a.uploadService.CreateBox(files, services.UploadOptions{
 		MaxDays:           parseInt(r.FormValue("max_days")),
 		MaxDownloads:      parseInt(r.FormValue("max_downloads")),
 		Password:          r.FormValue("password"),
 		ObfuscateMetadata: r.FormValue("obfuscate_metadata") == "on",
+		OwnerID:           ownerID,
+		CollectionID:      collectionID,
+		SkipSizeLimit:     isAdminUpload,
 	})
 	if err != nil {
 		a.logger.Warn("upload failed", "source", "user-upload", "severity", "warn", "code", 4001, "error", err.Error())

backend/libs/handlers/upload_stage3_test.go

@@ -194,7 +194,12 @@ func newTestApp(t *testing.T) (*App, func()) {
 		service.Close()
 		t.Fatalf("NewRenderer returned error: %v", err)
 	}
-	return NewApp(cfg, logger, renderer, service), func() {
+	authService, err := services.NewAuthService(service.DB(), cfg.BaseURL)
+	if err != nil {
+		service.Close()
+		t.Fatalf("NewAuthService returned error: %v", err)
+	}
+	return NewApp(cfg, logger, renderer, service, authService), func() {
 		if err := service.Close(); err != nil {
 			t.Fatalf("Close returned error: %v", err)
 		}

backend/libs/httpserver/server.go

@@ -22,8 +22,13 @@ func New(cfg config.Config, logger *slog.Logger) (*http.Server, error) {
 	if err != nil {
 		return nil, err
 	}
+	authService, err := services.NewAuthService(uploadService.DB(), cfg.BaseURL)
+	if err != nil {
+		uploadService.Close()
+		return nil, err
+	}
 	stopJobs := jobs.StartAll(cfg, logger, uploadService)
-	app := handlers.NewApp(cfg, logger, renderer, uploadService)
+	app := handlers.NewApp(cfg, logger, renderer, uploadService, authService)
 
 	router := http.NewServeMux()
 	app.RegisterRoutes(router)

backend/libs/services/auth.go

@@ -0,0 +1,579 @@
+package services
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/mail"
+	"os"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/bbolt"
+	"golang.org/x/crypto/argon2"
+)
+
+var (
+	usersBucket       = []byte("users")
+	userEmailsBucket  = []byte("user_emails")
+	sessionsBucket    = []byte("sessions")
+	invitesBucket     = []byte("invites")
+	collectionsBucket = []byte("collections")
+)
+
+const (
+	UserRoleAdmin = "admin"
+	UserRoleUser  = "user"
+
+	UserStatusActive   = "active"
+	UserStatusDisabled = "disabled"
+)
+
+var (
+	ErrInvalidCredentials = errors.New("invalid credentials")
+	ErrRegistrationClosed = errors.New("registration is closed")
+	ErrInviteInvalid      = errors.New("invite is invalid")
+	ErrUserDisabled       = errors.New("user is disabled")
+)
+
+type AuthService struct {
+	db      *bbolt.DB
+	baseURL string
+}
+
+type User struct {
+	ID           string    `json:"id"`
+	Username     string    `json:"username"`
+	Email        string    `json:"email"`
+	PasswordHash string    `json:"passwordHash"`
+	Role         string    `json:"role"`
+	Status       string    `json:"status"`
+	CreatedAt    time.Time `json:"createdAt"`
+	UpdatedAt    time.Time `json:"updatedAt"`
+}
+
+type PublicUser struct {
+	ID        string
+	Username  string
+	Email     string
+	Role      string
+	Status    string
+	CreatedAt time.Time
+}
+
+type Session struct {
+	ID        string    `json:"id"`
+	UserID    string    `json:"userId"`
+	TokenHash string    `json:"tokenHash"`
+	ExpiresAt time.Time `json:"expiresAt"`
+	CreatedAt time.Time `json:"createdAt"`
+}
+
+type Invite struct {
+	ID           string     `json:"id"`
+	UserID       string     `json:"userId,omitempty"`
+	Email        string     `json:"email"`
+	Role         string     `json:"role"`
+	TokenHash    string     `json:"tokenHash"`
+	CreatedBy    string     `json:"createdBy"`
+	CreatedAt    time.Time  `json:"createdAt"`
+	ExpiresAt    time.Time  `json:"expiresAt"`
+	UsedAt       *time.Time `json:"usedAt,omitempty"`
+	UsedByUserID string     `json:"usedByUserId,omitempty"`
+}
+
+type Collection struct {
+	ID        string    `json:"id"`
+	UserID    string    `json:"userId"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"createdAt"`
+	UpdatedAt time.Time `json:"updatedAt"`
+}
+
+type InviteResult struct {
+	Invite Invite
+	URL    string
+	Token  string
+}
+
+func NewAuthService(db *bbolt.DB, baseURL string) (*AuthService, error) {
+	service := &AuthService{db: db, baseURL: strings.TrimRight(baseURL, "/")}
+	err := db.Update(func(tx *bbolt.Tx) error {
+		for _, bucket := range [][]byte{usersBucket, userEmailsBucket, sessionsBucket, invitesBucket, collectionsBucket} {
+			if _, err := tx.CreateBucketIfNotExists(bucket); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return service, nil
+}
+
+func (s *AuthService) BootstrapAvailable() (bool, error) {
+	count := 0
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		return tx.Bucket(usersBucket).ForEach(func(_, _ []byte) error {
+			count++
+			return nil
+		})
+	})
+	return count == 0, err
+}
+
+func (s *AuthService) CreateBootstrapUser(username, email, password string) (User, error) {
+	available, err := s.BootstrapAvailable()
+	if err != nil {
+		return User{}, err
+	}
+	if !available {
+		return User{}, ErrRegistrationClosed
+	}
+	return s.createUser(username, email, password, UserRoleAdmin)
+}
+
+func (s *AuthService) Login(email, password string) (User, string, error) {
+	user, err := s.UserByEmail(email)
+	if err != nil {
+		return User{}, "", ErrInvalidCredentials
+	}
+	if user.Status != UserStatusActive {
+		return User{}, "", ErrUserDisabled
+	}
+	if !VerifyPasswordHash(user.PasswordHash, password) {
+		return User{}, "", ErrInvalidCredentials
+	}
+
+	token := randomID(32)
+	session := Session{
+		ID:        randomID(12),
+		UserID:    user.ID,
+		TokenHash: tokenHash(token),
+		CreatedAt: time.Now().UTC(),
+		ExpiresAt: time.Now().UTC().Add(30 * 24 * time.Hour),
+	}
+	err = s.db.Update(func(tx *bbolt.Tx) error {
+		data, err := json.Marshal(session)
+		if err != nil {
+			return err
+		}
+		return tx.Bucket(sessionsBucket).Put([]byte(session.ID), data)
+	})
+	return user, session.ID + "." + token, err
+}
+
+func (s *AuthService) UserForSession(raw string) (User, Session, error) {
+	sessionID, token, ok := strings.Cut(raw, ".")
+	if !ok || sessionID == "" || token == "" {
+		return User{}, Session{}, os.ErrNotExist
+	}
+
+	var session Session
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		data := tx.Bucket(sessionsBucket).Get([]byte(sessionID))
+		if data == nil {
+			return os.ErrNotExist
+		}
+		return json.Unmarshal(data, &session)
+	})
+	if err != nil {
+		return User{}, Session{}, err
+	}
+	if time.Now().UTC().After(session.ExpiresAt) || subtle.ConstantTimeCompare([]byte(tokenHash(token)), []byte(session.TokenHash)) != 1 {
+		return User{}, Session{}, os.ErrPermission
+	}
+	user, err := s.UserByID(session.UserID)
+	if err != nil {
+		return User{}, Session{}, err
+	}
+	if user.Status != UserStatusActive {
+		return User{}, Session{}, ErrUserDisabled
+	}
+	return user, session, nil
+}
+
+func (s *AuthService) Logout(raw string) error {
+	sessionID, _, ok := strings.Cut(raw, ".")
+	if !ok || sessionID == "" {
+		return nil
+	}
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		return tx.Bucket(sessionsBucket).Delete([]byte(sessionID))
+	})
+}
+
+func (s *AuthService) CreateInvite(email, role, createdBy string, expiresIn time.Duration) (InviteResult, error) {
+	email, err := normalizeEmail(email)
+	if err != nil {
+		return InviteResult{}, err
+	}
+	if role == "" {
+		role = UserRoleUser
+	}
+	if role != UserRoleAdmin && role != UserRoleUser {
+		role = UserRoleUser
+	}
+	if expiresIn <= 0 {
+		expiresIn = 7 * 24 * time.Hour
+	}
+
+	token := randomID(32)
+	invite := Invite{
+		ID:        randomID(12),
+		Email:     email,
+		Role:      role,
+		TokenHash: tokenHash(token),
+		CreatedBy: createdBy,
+		CreatedAt: time.Now().UTC(),
+		ExpiresAt: time.Now().UTC().Add(expiresIn),
+	}
+	err = s.saveInvite(invite)
+	if err != nil {
+		return InviteResult{}, err
+	}
+	return InviteResult{
+		Invite: invite,
+		Token:  token,
+		URL:    fmt.Sprintf("%s/invite/%s", s.baseURL, token),
+	}, nil
+}
+
+func (s *AuthService) AcceptInvite(token, username, password string) (User, error) {
+	invite, err := s.InviteByToken(token)
+	if err != nil {
+		return User{}, err
+	}
+	if invite.UsedAt != nil || time.Now().UTC().After(invite.ExpiresAt) {
+		return User{}, ErrInviteInvalid
+	}
+
+	var user User
+	if invite.UserID != "" {
+		user, err = s.UserByID(invite.UserID)
+		if err != nil {
+			return User{}, err
+		}
+		if err := s.SetPassword(user.ID, password); err != nil {
+			return User{}, err
+		}
+		user, _ = s.UserByID(user.ID)
+	} else {
+		user, err = s.createUser(username, invite.Email, password, invite.Role)
+		if err != nil {
+			return User{}, err
+		}
+	}
+
+	now := time.Now().UTC()
+	invite.UsedAt = &now
+	invite.UsedByUserID = user.ID
+	if err := s.saveInvite(invite); err != nil {
+		return User{}, err
+	}
+	return user, nil
+}
+
+func (s *AuthService) InviteByToken(token string) (Invite, error) {
+	hash := tokenHash(token)
+	var match Invite
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		return tx.Bucket(invitesBucket).ForEach(func(_, value []byte) error {
+			var invite Invite
+			if err := json.Unmarshal(value, &invite); err != nil {
+				return err
+			}
+			if subtle.ConstantTimeCompare([]byte(hash), []byte(invite.TokenHash)) == 1 {
+				match = invite
+			}
+			return nil
+		})
+	})
+	if err != nil {
+		return Invite{}, err
+	}
+	if match.ID == "" {
+		return Invite{}, ErrInviteInvalid
+	}
+	return match, nil
+}
+
+func (s *AuthService) CreatePasswordResetInvite(userID, createdBy string) (InviteResult, error) {
+	user, err := s.UserByID(userID)
+	if err != nil {
+		return InviteResult{}, err
+	}
+	result, err := s.CreateInvite(user.Email, user.Role, createdBy, 24*time.Hour)
+	if err != nil {
+		return InviteResult{}, err
+	}
+	result.Invite.UserID = user.ID
+	if err := s.saveInvite(result.Invite); err != nil {
+		return InviteResult{}, err
+	}
+	return result, nil
+}
+
+func (s *AuthService) ListUsers() ([]User, error) {
+	users := make([]User, 0)
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		return tx.Bucket(usersBucket).ForEach(func(_, value []byte) error {
+			var user User
+			if err := json.Unmarshal(value, &user); err != nil {
+				return err
+			}
+			users = append(users, user)
+			return nil
+		})
+	})
+	sort.Slice(users, func(i, j int) bool {
+		return users[i].CreatedAt.After(users[j].CreatedAt)
+	})
+	return users, err
+}
+
+func (s *AuthService) DisableUser(userID string, disabled bool) error {
+	user, err := s.UserByID(userID)
+	if err != nil {
+		return err
+	}
+	if disabled {
+		user.Status = UserStatusDisabled
+	} else {
+		user.Status = UserStatusActive
+	}
+	user.UpdatedAt = time.Now().UTC()
+	return s.saveUser(user)
+}
+
+func (s *AuthService) SetPassword(userID, password string) error {
+	if len(password) < 8 {
+		return fmt.Errorf("password must be at least 8 characters")
+	}
+	user, err := s.UserByID(userID)
+	if err != nil {
+		return err
+	}
+	user.PasswordHash = HashPassword(password)
+	user.UpdatedAt = time.Now().UTC()
+	return s.saveUser(user)
+}
+
+func (s *AuthService) UserByID(id string) (User, error) {
+	var user User
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		data := tx.Bucket(usersBucket).Get([]byte(id))
+		if data == nil {
+			return os.ErrNotExist
+		}
+		return json.Unmarshal(data, &user)
+	})
+	return user, err
+}
+
+func (s *AuthService) UserByEmail(email string) (User, error) {
+	email, err := normalizeEmail(email)
+	if err != nil {
+		return User{}, err
+	}
+	var userID string
+	err = s.db.View(func(tx *bbolt.Tx) error {
+		data := tx.Bucket(userEmailsBucket).Get([]byte(email))
+		if data == nil {
+			return os.ErrNotExist
+		}
+		userID = string(data)
+		return nil
+	})
+	if err != nil {
+		return User{}, err
+	}
+	return s.UserByID(userID)
+}
+
+func (s *AuthService) CreateCollection(userID, name string) (Collection, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return Collection{}, fmt.Errorf("collection name is required")
+	}
+	collection := Collection{
+		ID:        randomID(10),
+		UserID:    userID,
+		Name:      name,
+		CreatedAt: time.Now().UTC(),
+		UpdatedAt: time.Now().UTC(),
+	}
+	return collection, s.saveCollection(collection)
+}
+
+func (s *AuthService) ListCollections(userID string) ([]Collection, error) {
+	collections := make([]Collection, 0)
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		return tx.Bucket(collectionsBucket).ForEach(func(_, value []byte) error {
+			var collection Collection
+			if err := json.Unmarshal(value, &collection); err != nil {
+				return err
+			}
+			if collection.UserID == userID {
+				collections = append(collections, collection)
+			}
+			return nil
+		})
+	})
+	sort.Slice(collections, func(i, j int) bool {
+		return strings.ToLower(collections[i].Name) < strings.ToLower(collections[j].Name)
+	})
+	return collections, err
+}
+
+func (s *AuthService) CollectionOwnedBy(collectionID, userID string) bool {
+	if collectionID == "" {
+		return true
+	}
+	collection, err := s.CollectionByID(collectionID)
+	return err == nil && collection.UserID == userID
+}
+
+func (s *AuthService) CollectionByID(id string) (Collection, error) {
+	var collection Collection
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		data := tx.Bucket(collectionsBucket).Get([]byte(id))
+		if data == nil {
+			return os.ErrNotExist
+		}
+		return json.Unmarshal(data, &collection)
+	})
+	return collection, err
+}
+
+func (s *AuthService) PublicUser(user User) PublicUser {
+	return PublicUser{
+		ID:        user.ID,
+		Username:  user.Username,
+		Email:     user.Email,
+		Role:      user.Role,
+		Status:    user.Status,
+		CreatedAt: user.CreatedAt,
+	}
+}
+
+func (s *AuthService) createUser(username, email, password, role string) (User, error) {
+	username = strings.TrimSpace(username)
+	if username == "" {
+		return User{}, fmt.Errorf("username is required")
+	}
+	email, err := normalizeEmail(email)
+	if err != nil {
+		return User{}, err
+	}
+	if len(password) < 8 {
+		return User{}, fmt.Errorf("password must be at least 8 characters")
+	}
+	if role != UserRoleAdmin && role != UserRoleUser {
+		role = UserRoleUser
+	}
+
+	now := time.Now().UTC()
+	user := User{
+		ID:           randomID(12),
+		Username:     username,
+		Email:        email,
+		PasswordHash: HashPassword(password),
+		Role:         role,
+		Status:       UserStatusActive,
+		CreatedAt:    now,
+		UpdatedAt:    now,
+	}
+	return user, s.db.Update(func(tx *bbolt.Tx) error {
+		if existing := tx.Bucket(userEmailsBucket).Get([]byte(email)); existing != nil {
+			return fmt.Errorf("email is already registered")
+		}
+		data, err := json.Marshal(user)
+		if err != nil {
+			return err
+		}
+		if err := tx.Bucket(usersBucket).Put([]byte(user.ID), data); err != nil {
+			return err
+		}
+		return tx.Bucket(userEmailsBucket).Put([]byte(email), []byte(user.ID))
+	})
+}
+
+func (s *AuthService) saveUser(user User) error {
+	data, err := json.Marshal(user)
+	if err != nil {
+		return err
+	}
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		return tx.Bucket(usersBucket).Put([]byte(user.ID), data)
+	})
+}
+
+func (s *AuthService) saveInvite(invite Invite) error {
+	data, err := json.Marshal(invite)
+	if err != nil {
+		return err
+	}
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		return tx.Bucket(invitesBucket).Put([]byte(invite.ID), data)
+	})
+}
+
+func (s *AuthService) saveCollection(collection Collection) error {
+	data, err := json.Marshal(collection)
+	if err != nil {
+		return err
+	}
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		return tx.Bucket(collectionsBucket).Put([]byte(collection.ID), data)
+	})
+}
+
+func normalizeEmail(email string) (string, error) {
+	email = strings.ToLower(strings.TrimSpace(email))
+	if email == "" {
+		return "", fmt.Errorf("email is required")
+	}
+	if _, err := mail.ParseAddress(email); err != nil {
+		return "", fmt.Errorf("email is invalid")
+	}
+	return email, nil
+}
+
+func tokenHash(token string) string {
+	sum := sha256.Sum256([]byte("warpbox-session:" + token))
+	return hex.EncodeToString(sum[:])
+}
+
+func HashPassword(password string) string {
+	salt := make([]byte, 16)
+	if _, err := rand.Read(salt); err != nil {
+		salt = []byte(randomID(16))[:16]
+	}
+	hash := argon2.IDKey([]byte(password), salt, 1, 64*1024, 4, 32)
+	return "argon2id$v=19$m=65536,t=1,p=4$" + base64.RawStdEncoding.EncodeToString(salt) + "$" + base64.RawStdEncoding.EncodeToString(hash)
+}
+
+func VerifyPasswordHash(encoded, password string) bool {
+	parts := strings.Split(encoded, "$")
+	if len(parts) != 5 || parts[0] != "argon2id" {
+		return false
+	}
+	salt, err := base64.RawStdEncoding.DecodeString(parts[3])
+	if err != nil {
+		return false
+	}
+	expected, err := base64.RawStdEncoding.DecodeString(parts[4])
+	if err != nil {
+		return false
+	}
+	actual := argon2.IDKey([]byte(password), salt, 1, 64*1024, 4, uint32(len(expected)))
+	return subtle.ConstantTimeCompare(actual, expected) == 1
+}

backend/libs/services/auth_test.go

@@ -0,0 +1,123 @@
+package services
+
+import (
+	"log/slog"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestPasswordHashVerification(t *testing.T) {
+	hash := HashPassword("correct-horse")
+	if !VerifyPasswordHash(hash, "correct-horse") {
+		t.Fatalf("VerifyPasswordHash rejected the correct password")
+	}
+	if VerifyPasswordHash(hash, "wrong-password") {
+		t.Fatalf("VerifyPasswordHash accepted the wrong password")
+	}
+}
+
+func TestBootstrapCreatesAdminAndClosesRegistration(t *testing.T) {
+	auth := newTestAuthService(t)
+	available, err := auth.BootstrapAvailable()
+	if err != nil {
+		t.Fatalf("BootstrapAvailable returned error: %v", err)
+	}
+	if !available {
+		t.Fatalf("BootstrapAvailable = false, want true")
+	}
+
+	user, err := auth.CreateBootstrapUser("daniel", "daniel@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	if user.Role != UserRoleAdmin {
+		t.Fatalf("role = %q, want admin", user.Role)
+	}
+
+	if _, err := auth.CreateBootstrapUser("other", "other@example.test", "password123"); err == nil {
+		t.Fatalf("second bootstrap unexpectedly succeeded")
+	}
+}
+
+func TestLoginSessionAndDisabledUser(t *testing.T) {
+	auth := newTestAuthService(t)
+	user, err := auth.CreateBootstrapUser("daniel", "daniel@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	if _, _, err := auth.Login("daniel@example.test", "wrong"); err == nil {
+		t.Fatalf("Login accepted wrong password")
+	}
+
+	_, token, err := auth.Login("daniel@example.test", "password123")
+	if err != nil {
+		t.Fatalf("Login returned error: %v", err)
+	}
+	sessionUser, _, err := auth.UserForSession(token)
+	if err != nil {
+		t.Fatalf("UserForSession returned error: %v", err)
+	}
+	if sessionUser.ID != user.ID {
+		t.Fatalf("session user = %q, want %q", sessionUser.ID, user.ID)
+	}
+
+	if err := auth.DisableUser(user.ID, true); err != nil {
+		t.Fatalf("DisableUser returned error: %v", err)
+	}
+	if _, _, err := auth.UserForSession(token); err == nil {
+		t.Fatalf("disabled user session still resolved")
+	}
+}
+
+func TestInviteAcceptsOnceAndResetChangesPassword(t *testing.T) {
+	auth := newTestAuthService(t)
+	admin, err := auth.CreateBootstrapUser("admin", "admin@example.test", "password123")
+	if err != nil {
+		t.Fatalf("CreateBootstrapUser returned error: %v", err)
+	}
+	invite, err := auth.CreateInvite("friend@example.test", UserRoleUser, admin.ID, time.Hour)
+	if err != nil {
+		t.Fatalf("CreateInvite returned error: %v", err)
+	}
+	user, err := auth.AcceptInvite(invite.Token, "friend", "password123")
+	if err != nil {
+		t.Fatalf("AcceptInvite returned error: %v", err)
+	}
+	if user.Email != "friend@example.test" {
+		t.Fatalf("email = %q, want friend@example.test", user.Email)
+	}
+	if _, err := auth.AcceptInvite(invite.Token, "friend", "password123"); err == nil {
+		t.Fatalf("AcceptInvite allowed token reuse")
+	}
+
+	reset, err := auth.CreatePasswordResetInvite(user.ID, admin.ID)
+	if err != nil {
+		t.Fatalf("CreatePasswordResetInvite returned error: %v", err)
+	}
+	if _, err := auth.AcceptInvite(reset.Token, "", "newpassword123"); err != nil {
+		t.Fatalf("AcceptInvite reset returned error: %v", err)
+	}
+	if _, _, err := auth.Login("friend@example.test", "newpassword123"); err != nil {
+		t.Fatalf("Login with reset password returned error: %v", err)
+	}
+}
+
+func newTestAuthService(t *testing.T) *AuthService {
+	t.Helper()
+	root := t.TempDir()
+	upload, err := NewUploadService(1024*1024, filepath.Join(root, "data"), "http://example.test", slog.Default())
+	if err != nil {
+		t.Fatalf("NewUploadService returned error: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := upload.Close(); err != nil {
+			t.Fatalf("Close returned error: %v", err)
+		}
+	})
+	auth, err := NewAuthService(upload.DB(), "http://example.test")
+	if err != nil {
+		t.Fatalf("NewAuthService returned error: %v", err)
+	}
+	return auth
+}

backend/libs/services/upload.go

@@ -14,6 +14,7 @@ import (
 	"mime/multipart"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 	"time"
 
@@ -37,10 +38,16 @@ type UploadOptions struct {
 	MaxDownloads      int
 	Password          string
 	ObfuscateMetadata bool
+	OwnerID           string
+	CollectionID      string
+	SkipSizeLimit     bool
 }
 
 type Box struct {
 	ID              string    `json:"id"`
+	OwnerID         string    `json:"ownerId,omitempty"`
+	CollectionID    string    `json:"collectionId,omitempty"`
+	Title           string    `json:"title,omitempty"`
 	CreatedAt       time.Time `json:"createdAt"`
 	ExpiresAt       time.Time `json:"expiresAt"`
 	MaxDownloads    int       `json:"maxDownloads"`
@@ -93,6 +100,7 @@ type AdminStats struct {
 
 type AdminBox struct {
 	ID             string
+	OwnerID        string
 	CreatedAt      time.Time
 	ExpiresAt      time.Time
 	FileCount      int
@@ -104,6 +112,12 @@ type AdminBox struct {
 	Expired        bool
 }
 
+type UserBox struct {
+	Box            Box
+	CollectionName string
+	TotalSizeLabel string
+}
+
 func NewUploadService(maxUploadSize int64, dataDir, baseURL string, logger *slog.Logger) (*UploadService, error) {
 	filesDir := filepath.Join(dataDir, "files")
 	dbDir := filepath.Join(dataDir, "db")
@@ -141,6 +155,10 @@ func (s *UploadService) Close() error {
 	return s.db.Close()
 }
 
+func (s *UploadService) DB() *bbolt.DB {
+	return s.db
+}
+
 func (s *UploadService) MaxUploadSize() int64 {
 	return s.maxUploadSize
 }
@@ -166,6 +184,8 @@ func (s *UploadService) CreateBox(files []*multipart.FileHeader, opts UploadOpti
 
 	box := Box{
 		ID:           randomID(10),
+		OwnerID:      strings.TrimSpace(opts.OwnerID),
+		CollectionID: strings.TrimSpace(opts.CollectionID),
 		CreatedAt:    time.Now().UTC(),
 		ExpiresAt:    time.Now().UTC().Add(time.Duration(opts.MaxDays) * 24 * time.Hour),
 		MaxDownloads: opts.MaxDownloads,
@@ -186,9 +206,16 @@ func (s *UploadService) CreateBox(files []*multipart.FileHeader, opts UploadOpti
 	}
 
 	for _, header := range files {
+		if !opts.SkipSizeLimit {
 			if err := s.ValidateSize(header.Size); err != nil {
 				return UploadResult{}, err
 			}
+		}
+
+		maxSize := s.maxUploadSize
+		if opts.SkipSizeLimit {
+			maxSize = 0
+		}
 
 		file, err := header.Open()
 		if err != nil {
@@ -203,7 +230,7 @@ func (s *UploadService) CreateBox(files []*multipart.FileHeader, opts UploadOpti
 			contentType = "application/octet-stream"
 		}
 
-		if err := writeUploadedFile(storedPath, file, s.maxUploadSize); err != nil {
+		if err := writeUploadedFile(storedPath, file, maxSize); err != nil {
 			file.Close()
 			return UploadResult{}, err
 		}
@@ -314,6 +341,7 @@ func (s *UploadService) AdminBoxes(limit int) ([]AdminBox, error) {
 		}
 		rows = append(rows, AdminBox{
 			ID:             box.ID,
+			OwnerID:        box.OwnerID,
 			CreatedAt:      box.CreatedAt,
 			ExpiresAt:      box.ExpiresAt,
 			FileCount:      len(box.Files),
@@ -328,6 +356,85 @@ func (s *UploadService) AdminBoxes(limit int) ([]AdminBox, error) {
 	return rows, nil
 }
 
+func (s *UploadService) UserBoxes(userID string, collectionNames map[string]string) ([]UserBox, error) {
+	boxes, err := s.ListBoxes(0)
+	if err != nil {
+		return nil, err
+	}
+
+	rows := make([]UserBox, 0)
+	for _, box := range boxes {
+		if box.OwnerID != userID {
+			continue
+		}
+		var size int64
+		for _, file := range box.Files {
+			size += file.Size
+		}
+		rows = append(rows, UserBox{
+			Box:            box,
+			CollectionName: collectionNames[box.CollectionID],
+			TotalSizeLabel: helpers.FormatBytes(size),
+		})
+	}
+	sort.Slice(rows, func(i, j int) bool {
+		return rows[i].Box.CreatedAt.After(rows[j].Box.CreatedAt)
+	})
+	return rows, nil
+}
+
+func (s *UploadService) UserStorageUsed(userID string) (int64, error) {
+	boxes, err := s.ListBoxes(0)
+	if err != nil {
+		return 0, err
+	}
+	var total int64
+	for _, box := range boxes {
+		if box.OwnerID != userID {
+			continue
+		}
+		for _, file := range box.Files {
+			total += file.Size
+		}
+	}
+	return total, nil
+}
+
+func (s *UploadService) RenameOwnedBox(boxID, userID, title string) error {
+	box, err := s.GetBox(boxID)
+	if err != nil {
+		return err
+	}
+	if box.OwnerID != userID {
+		return os.ErrPermission
+	}
+	box.Title = strings.TrimSpace(title)
+	return s.SaveBox(box)
+}
+
+func (s *UploadService) MoveOwnedBox(boxID, userID, collectionID string) error {
+	box, err := s.GetBox(boxID)
+	if err != nil {
+		return err
+	}
+	if box.OwnerID != userID {
+		return os.ErrPermission
+	}
+	box.CollectionID = strings.TrimSpace(collectionID)
+	return s.SaveBox(box)
+}
+
+func (s *UploadService) DeleteOwnedBox(boxID, userID string) error {
+	box, err := s.GetBox(boxID)
+	if err != nil {
+		return err
+	}
+	if box.OwnerID != userID {
+		return os.ErrPermission
+	}
+	return s.DeleteBoxWithSource(boxID, "user-delete")
+}
+
 func (s *UploadService) DeleteBox(boxID string) error {
 	return s.DeleteBoxWithSource(boxID, "admin")
 }
@@ -518,12 +625,17 @@ func writeUploadedFile(path string, source multipart.File, maxSize int64) error
 	}
 	defer target.Close()
 
-	written, err := io.Copy(target, io.LimitReader(source, maxSize+1))
+	var written int64
+	if maxSize <= 0 {
+		written, err = io.Copy(target, source)
+	} else {
+		written, err = io.Copy(target, io.LimitReader(source, maxSize+1))
+	}
 	if err != nil {
 		os.Remove(path)
 		return err
 	}
-	if written > maxSize {
+	if maxSize > 0 && written > maxSize {
 		os.Remove(path)
 		return fmt.Errorf("file exceeds max upload size")
 	}

backend/libs/web/renderer.go

@@ -20,6 +20,7 @@ type PageData struct {
 	Description string
 	ImageURL    string
 	CurrentYear int
+	CurrentUser any
 	Data        any
 }
 

backend/static/css/app.css

@@ -90,12 +90,17 @@ svg {
 
 .brand,
 .nav-links,
-.footer-links {
+.footer-links,
+.inline-form {
   display: inline-flex;
   align-items: center;
   gap: 0.5rem;
 }
 
+.inline-form {
+  margin: 0;
+}
+
 .brand {
   font-weight: 650;
   text-decoration: none;
@@ -171,6 +176,125 @@ h1 {
   padding: 1.5rem;
 }
 
+.auth-view {
+  width: min(28rem, calc(100% - 2rem));
+  min-height: calc(100vh - 7.25rem);
+  margin: 0 auto;
+  padding: 3rem 0;
+  display: grid;
+  place-items: center;
+}
+
+.auth-card {
+  box-shadow: var(--shadow);
+}
+
+.kicker {
+  margin: 0 0 0.5rem;
+  color: var(--muted-foreground);
+  font-size: 0.76rem;
+  font-weight: 700;
+  letter-spacing: 0;
+  text-transform: uppercase;
+}
+
+.muted-copy,
+.auth-alt {
+  color: var(--muted-foreground);
+  font-size: 0.9rem;
+  line-height: 1.5;
+}
+
+.stack-form {
+  display: grid;
+  gap: 0.9rem;
+  margin-top: 1rem;
+}
+
+.stack-form label,
+.inline-controls label,
+.collection-create label {
+  display: grid;
+  gap: 0.35rem;
+  color: var(--muted-foreground);
+  font-size: 0.82rem;
+}
+
+.form-error {
+  margin: 0;
+  color: #fca5a5;
+  font-size: 0.86rem;
+}
+
+.app-shell {
+  width: min(86rem, calc(100% - 2rem));
+  margin: 0 auto;
+  padding: 2rem 0;
+  display: grid;
+  grid-template-columns: 14rem minmax(0, 1fr);
+  gap: 1.5rem;
+}
+
+.app-sidebar {
+  position: sticky;
+  top: 5rem;
+  align-self: start;
+  display: grid;
+  gap: 0.5rem;
+}
+
+.sidebar-link {
+  padding: 0.62rem 0.75rem;
+  border: 1px solid transparent;
+  border-radius: var(--radius);
+  color: var(--muted-foreground);
+  text-decoration: none;
+}
+
+.sidebar-link:hover,
+.sidebar-link.is-active {
+  border-color: var(--border);
+  background: var(--muted);
+  color: var(--foreground);
+}
+
+.collection-create {
+  display: grid;
+  gap: 0.6rem;
+  margin-top: 1rem;
+}
+
+.app-main {
+  min-width: 0;
+  display: grid;
+  gap: 1rem;
+}
+
+.compact-upload .drop-zone {
+  min-height: 11rem;
+}
+
+.dashboard-options {
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+}
+
+.collection-tabs,
+.inline-controls {
+  display: flex;
+  align-items: end;
+  flex-wrap: wrap;
+  gap: 0.65rem;
+}
+
+.inline-controls input,
+.inline-controls select {
+  min-width: 15rem;
+}
+
+.compact-input {
+  width: 10rem;
+}
+
 .drop-zone {
   min-height: 19rem;
   display: grid;

backend/templates/layouts/base.html

@@ -27,6 +27,13 @@
         <span>{{.AppName}}</span>
       </a>
       <div class="nav-links">
+        {{if .CurrentUser}}
+        <a class="button button-ghost" href="/app">My files</a>
+        <a class="button button-ghost" href="/account/settings">Account</a>
+        <form action="/logout" method="post" class="inline-form"><button class="button button-outline" type="submit">Logout</button></form>
+        {{else}}
+        <a class="button button-ghost" href="/login">Login</a>
+        {{end}}
         <a class="button button-ghost" href="/api">API</a>
         <a class="button button-outline" href="/healthz">Health</a>
       </div>
@@ -39,7 +46,7 @@
 
   <footer class="site-footer">
     <span>{{.AppName}} · {{.CurrentYear}} · self-hosted</span>
-    <span class="footer-links"><a href="/">Upload</a><a href="/healthz">Health</a></span>
+    <span class="footer-links"><a href="/">Upload</a>{{if .CurrentUser}}<a href="/app">My files</a>{{end}}<a href="/healthz">Health</a></span>
   </footer>
 </body>
 </html>

backend/templates/pages/account.html

@@ -0,0 +1,19 @@
+{{define "account.html"}}{{template "base" .}}{{end}}
+
+{{define "content"}}
+<section class="auth-view" aria-labelledby="account-title">
+  <div class="card auth-card">
+    <div class="card-content">
+      <p class="kicker">Account</p>
+      <h1 id="account-title">Settings</h1>
+      <p class="muted-copy">{{.Data.Email}} · {{.Data.Role}}</p>
+      <form class="stack-form" action="/account/password" method="post">
+        <label><span>Current password</span><input type="password" name="current_password" autocomplete="current-password" required></label>
+        <label><span>New password</span><input type="password" name="new_password" autocomplete="new-password" minlength="8" required></label>
+        <button class="button button-primary" type="submit">Update password</button>
+      </form>
+      <p class="muted-copy">Public forgot-password is deferred until SMTP support is added. Admins can generate reset links.</p>
+    </div>
+  </div>
+</section>
+{{end}}

backend/templates/pages/admin.html

@@ -8,6 +8,7 @@
       <h1 id="admin-title">Admin overview</h1>
     </div>
     <form action="/admin/logout" method="post">
+      <a class="button button-outline" href="/admin/users">Users</a>
       <button class="button button-outline" type="submit">Logout</button>
     </form>
   </div>
@@ -54,6 +55,7 @@
           <thead>
             <tr>
               <th>Box</th>
+              <th>Owner</th>
               <th>Files</th>
               <th>Size</th>
               <th>Downloads</th>
@@ -67,6 +69,7 @@
             {{range .Data.Boxes}}
               <tr>
                 <td><code>{{.ID}}</code></td>
+                <td>{{.Owner}}</td>
                 <td>{{.FileCount}}</td>
                 <td>{{.TotalSizeLabel}}</td>
                 <td>{{.DownloadCount}}{{if .MaxDownloads}} / {{.MaxDownloads}}{{end}}</td>
@@ -84,7 +87,7 @@
                 </td>
               </tr>
             {{else}}
-              <tr><td colspan="8">No uploads yet.</td></tr>
+              <tr><td colspan="9">No uploads yet.</td></tr>
             {{end}}
           </tbody>
         </table>

backend/templates/pages/admin_users.html

@@ -0,0 +1,67 @@
+{{define "admin_users.html"}}{{template "base" .}}{{end}}
+
+{{define "content"}}
+<section class="admin-view" aria-labelledby="admin-users-title">
+  <div class="admin-header">
+    <div>
+      <p class="kicker">Operator console</p>
+      <h1 id="admin-users-title">Users</h1>
+    </div>
+    <div class="result-actions">
+      <a class="button button-outline" href="/admin">Overview</a>
+      <a class="button button-outline" href="/admin/files">Files</a>
+    </div>
+  </div>
+
+  <div class="card admin-table-card">
+    <div class="card-content">
+      <div class="table-header">
+        <div>
+          <h2>Create invite</h2>
+          <p>Copy the generated link and send it manually. SMTP delivery comes later.</p>
+        </div>
+      </div>
+      {{if .Data.LastInviteURL}}
+        <p class="manage-link"><span>Invite link:</span> <a href="{{.Data.LastInviteURL}}">{{.Data.LastInviteURL}}</a></p>
+      {{end}}
+      <form class="inline-controls" action="/admin/invites" method="post">
+        <label><span>Email</span><input type="email" name="email" required></label>
+        <label><span>Role</span><select name="role"><option value="user">User</option><option value="admin">Admin</option></select></label>
+        <button class="button button-primary" type="submit">Create invite</button>
+      </form>
+    </div>
+  </div>
+
+  <div class="card admin-table-card">
+    <div class="card-content">
+      <div class="table-header"><h2>Users</h2><p>Disable accounts or create reset links.</p></div>
+      <div class="admin-table-wrap">
+        <table class="admin-table">
+          <thead><tr><th>User</th><th>Email</th><th>Role</th><th>Status</th><th>Joined</th><th>Actions</th></tr></thead>
+          <tbody>
+            {{range .Data.Users}}
+              <tr>
+                <td>{{.Username}}</td>
+                <td>{{.Email}}</td>
+                <td>{{.Role}}</td>
+                <td><span class="badge">{{.Status}}</span></td>
+                <td>{{.CreatedAt}}</td>
+                <td class="table-actions">
+                  {{if eq .Status "disabled"}}
+                    <form action="/admin/users/{{.ID}}/disable?disabled=false" method="post"><button class="button button-outline" type="submit">Reactivate</button></form>
+                  {{else}}
+                    <form action="/admin/users/{{.ID}}/disable" method="post"><button class="button button-danger" type="submit">Disable</button></form>
+                  {{end}}
+                  <form action="/admin/users/{{.ID}}/reset" method="post"><button class="button button-outline" type="submit">Reset link</button></form>
+                </td>
+              </tr>
+            {{else}}
+              <tr><td colspan="6">No users yet.</td></tr>
+            {{end}}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  </div>
+</section>
+{{end}}

backend/templates/pages/auth.html

@@ -0,0 +1,43 @@
+{{define "auth.html"}}{{template "base" .}}{{end}}
+
+{{define "content"}}
+<section class="auth-view" aria-labelledby="auth-title">
+  <div class="card auth-card">
+    <div class="card-content">
+      {{if eq .Data.Mode "register"}}
+        <p class="kicker">Instance bootstrap</p>
+        <h1 id="auth-title">Create the admin account</h1>
+        <p class="muted-copy">The first user becomes the instance admin. Registration closes after this account is created.</p>
+        <form class="stack-form" action="/register" method="post">
+          {{if .Data.Error}}<p class="form-error">{{.Data.Error}}</p>{{end}}
+          <label><span>Username</span><input name="username" autocomplete="username" required></label>
+          <label><span>Email</span><input type="email" name="email" autocomplete="email" required></label>
+          <label><span>Password</span><input type="password" name="password" autocomplete="new-password" minlength="8" required></label>
+          <button class="button button-primary" type="submit">Create admin</button>
+        </form>
+      {{else if eq .Data.Mode "invite"}}
+        <p class="kicker">{{if .Data.IsReset}}Password reset{{else}}Invite{{end}}</p>
+        <h1 id="auth-title">{{if .Data.IsReset}}Choose a new password{{else}}Create your account{{end}}</h1>
+        {{if .Data.Email}}<p class="muted-copy">{{.Data.Email}}</p>{{end}}
+        <form class="stack-form" action="/invite/{{.Data.Token}}" method="post">
+          {{if .Data.Error}}<p class="form-error">{{.Data.Error}}</p>{{end}}
+          {{if not .Data.IsReset}}<label><span>Username</span><input name="username" autocomplete="username" required></label>{{end}}
+          <label><span>Password</span><input type="password" name="password" autocomplete="new-password" minlength="8" required></label>
+          <button class="button button-primary" type="submit">Accept invite</button>
+        </form>
+      {{else}}
+        <p class="kicker">Account</p>
+        <h1 id="auth-title">Sign in</h1>
+        <form class="stack-form" action="/login" method="post">
+          {{if .Data.Error}}<p class="form-error">{{.Data.Error}}</p>{{end}}
+          <input type="hidden" name="next" value="{{.Data.ReturnPath}}">
+          <label><span>Email</span><input type="email" name="email" autocomplete="email" required></label>
+          <label><span>Password</span><input type="password" name="password" autocomplete="current-password" required></label>
+          <button class="button button-primary" type="submit">Sign in</button>
+        </form>
+      {{end}}
+      <p class="auth-alt"><a href="/">Back to upload</a></p>
+    </div>
+  </div>
+</section>
+{{end}}

backend/templates/pages/dashboard.html

@@ -0,0 +1,70 @@
+{{define "dashboard.html"}}{{template "base" .}}{{end}}
+
+{{define "content"}}
+<section class="app-shell" aria-labelledby="dashboard-title">
+  <aside class="app-sidebar">
+    <a class="sidebar-link is-active" href="/app">Dashboard</a>
+    <a class="sidebar-link" href="/account/settings">Settings</a>
+    {{if eq .Data.User.Role "admin"}}<a class="sidebar-link" href="/admin">Admin</a>{{end}}
+    <form class="collection-create" action="/app/collections" method="post">
+      <label>
+        <span>New collection</span>
+        <input name="name" placeholder="Projects">
+      </label>
+      <button class="button button-outline" type="submit">Create</button>
+    </form>
+  </aside>
+
+  <div class="app-main">
+    <div class="admin-header">
+      <div>
+        <p class="kicker">Personal space</p>
+        <h1 id="dashboard-title">My files</h1>
+        <p class="muted-copy">{{.Data.StorageUsed}} used · max file size {{.Data.MaxUploadSize}}</p>
+      </div>
+      <a class="button button-primary" href="/">Upload files</a>
+    </div>
+
+    <div class="collection-tabs">
+      <a class="button {{if not .Data.Selected}}button-primary{{else}}button-outline{{end}}" href="/app">All</a>
+      {{range .Data.Collections}}
+        <a class="button {{if eq $.Data.Selected .ID}}button-primary{{else}}button-outline{{end}}" href="/app?collection={{.ID}}">{{.Name}}</a>
+      {{end}}
+    </div>
+
+    <div class="card admin-table-card">
+      <div class="card-content">
+        <div class="table-header"><h2>Owned boxes</h2><p>Collections organize boxes. Shared links remain unlisted.</p></div>
+        <div class="admin-table-wrap">
+          <table class="admin-table">
+            <thead><tr><th>Title</th><th>Collection</th><th>Files</th><th>Size</th><th>Created</th><th>Expires</th><th>Actions</th></tr></thead>
+            <tbody>
+              {{range .Data.Boxes}}
+                <tr>
+                  <td class="file-name">{{.Title}}</td>
+                  <td>{{if .CollectionName}}{{.CollectionName}}{{else}}Unsorted{{end}}</td>
+                  <td>{{.FileCount}}</td>
+                  <td>{{.Size}}</td>
+                  <td>{{.CreatedAt}}</td>
+                  <td>{{.ExpiresAt}}</td>
+                  <td class="table-actions">
+                    <a class="button button-outline" href="{{.URL}}" target="_blank" rel="noopener noreferrer">Open</a>
+                    <form action="/app/boxes/{{.ID}}/rename" method="post"><input class="compact-input" name="title" placeholder="Rename"><button class="button button-outline" type="submit">Save</button></form>
+                    <form action="/app/boxes/{{.ID}}/move" method="post">
+                      <select name="collection_id"><option value="">Unsorted</option>{{range $.Data.Collections}}<option value="{{.ID}}">{{.Name}}</option>{{end}}</select>
+                      <button class="button button-outline" type="submit">Move</button>
+                    </form>
+                    <form action="/app/boxes/{{.ID}}/delete" method="post"><button class="button button-danger" type="submit">Delete</button></form>
+                  </td>
+                </tr>
+              {{else}}
+                <tr><td colspan="7">You have no boxes yet.</td></tr>
+              {{end}}
+            </tbody>
+          </table>
+        </div>
+      </div>
+    </div>
+  </div>
+</section>
+{{end}}

backend/templates/pages/home.html

@@ -15,7 +15,7 @@
         </span>
         <span class="drop-title">Drop files to upload</span>
         <span class="drop-copy">or click to browse</span>
-        <span class="drop-meta">Max file size: {{.Data.MaxUploadSize}} · Links expire in 7 days</span>
+        <span class="drop-meta">{{if .Data.IsAdmin}}Admin upload: no file size limit{{else}}Max file size: {{.Data.MaxUploadSize}}{{end}} · Links expire in 7 days</span>
         <input id="file-input" name="file" type="file" multiple>
       </label>
 
@@ -25,6 +25,15 @@
           Advanced options
         </summary>
         <div class="option-grid">
+          {{if .CurrentUser}}
+          <label>
+            <span>Collection</span>
+            <select name="collection_id">
+              <option value="">Unsorted</option>
+              {{range .Data.Collections}}<option value="{{.ID}}">{{.Name}}</option>{{end}}
+            </select>
+          </label>
+          {{end}}
           <label>
             <span>Expires in</span>
             <select name="max_days">