feat(auth): support API tokens and bearer token authentication

- Add backend services to create, list, and delete API tokens.
- Implement Bearer token authentication to resolve tokens to users.
- Register HTTP routes for managing user tokens under `/account/tokens`.
- Add tests to verify that uploads with valid Bearer tokens associate the upload with the correct user, while invalid tokens fall back to anonymous uploads.

backend/libs/services/settings.go

@@ -3,6 +3,7 @@ package services
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"net"
 	"strconv"
 	"strings"
@@ -431,6 +432,7 @@ func GigabytesToBytes(value float64) int64 {
 
 func FormatMegabytesFromBytes(value int64) string {
 	mb := float64(value) / 1024 / 1024
+	mb = math.Round(mb*100) / 100
 	return FormatMegabytesLabel(mb)
 }