refactor: extract models/routes and env-based server config

- Move API request/response structs into new lib/models package
- Centralize Gin route registration in lib/routing to simplify wiring
- Add lib/server config helper to allow WARPBOX_BOX_POLL_INTERVAL_MS override
- Improves modularity and makes polling behavior configurable per environmentrefactor: extract models/routes and env-based server config

- Move API request/response structs into new lib/models package
- Centralize Gin route registration in lib/routing to simplify wiring
- Add lib/server config helper to allow WARPBOX_BOX_POLL_INTERVAL_MS override
- Improves modularity and makes polling behavior configurable per environment

templates/box.html

@@ -40,7 +40,7 @@
                     <code>/box/{{ .BoxID }}</code>
                 </div>
 
-                <div class="win98-panel box-panel" data-box-id="{{ .BoxID }}">
+                <div class="win98-panel box-panel" data-box-id="{{ .BoxID }}" data-poll-ms="{{ .PollMS }}">
                     {{ if .Files }}
                         <div class="box-file-grid" aria-label="Uploaded files">
                             {{ range .Files }}

templates/index.html

@@ -44,15 +44,15 @@
                             <span id="upload-file-count" class="upload-file-count">0 files</span>
                         </div>
 
-                        <div class="upload-file-list" aria-live="polite" aria-label="Selected files">
-                            <p class="upload-empty-state">No files selected</p>
-                        </div>
-
                         <div class="upload-result is-hidden" aria-live="polite">
                             <span class="upload-result-label">Folder link</span>
                             <a id="upload-box-link" class="upload-result-link is-empty" href="#" aria-disabled="true">Waiting for upload</a>
                             <button id="upload-share-button" class="win98-button upload-share-button" type="button" disabled>Share</button>
                         </div>
+
+                        <div class="upload-file-list" aria-live="polite" aria-label="Selected files">
+                            <p class="upload-empty-state">No files selected</p>
+                        </div>
                     </div>
 
                     <footer class="upload-actions">