feat: frontend MVP — auth, timeline, upload, albums, admin, image viewer

Backend:
- user roles (DB + JWT + first-user-is-admin)
- volume-aware file resolver (multi-volume asset serving)
- directory scanner uses volume URI directly
- date-summary endpoint (capture date from EXIF)
- timeline ordered by capture date
- list endpoints: volumes, plugins, pipelines, library paths
- delete endpoints: volumes, library paths
- configurable upload body limit (MAX_UPLOAD_BYTES)

Frontend:
- auth: login/register, token refresh, role-based admin gate
- timeline: date-grouped grid, infinite scroll, date scrubber
- image viewer: fullscreen zoom/pan/pinch, metadata sidebar
- upload: drag-drop, sequential upload, progress tracking
- albums: create, add/remove photos, asset picker dialog
- admin: storage (import library), jobs (pagination, error details),
  plugins (list + toggle), pipelines, sidecars, duplicates
- multi-select mode with add-to-album action
- TanStack Query for all data fetching

k-photos-frontend/lib/types.ts

@@ -0,0 +1,158 @@
+export interface UserResponse {
+  id: string
+  username: string
+  email: string
+  role: string
+  created_at: string
+}
+
+export interface AuthResponse {
+  token: string
+  refresh_token: string
+  user: UserResponse
+}
+
+export interface AssetResponse {
+  id: string
+  asset_type: string
+  mime_type: string
+  file_size: number
+  is_processed: boolean
+  created_at: string
+  metadata: Record<string, unknown>
+}
+
+export interface TimelineResponse {
+  assets: AssetResponse[]
+  total: number
+}
+
+export interface DateCountEntry {
+  date: string
+  count: number
+}
+
+export interface DateSummaryResponse {
+  dates: DateCountEntry[]
+}
+
+export interface AlbumResponse {
+  id: string
+  title: string
+  description: string
+  creator_id: string
+  asset_count: number
+  asset_ids: string[]
+  created_at: string
+}
+
+export interface IngestResponse {
+  asset: AssetResponse
+  session_id: string
+}
+
+export interface LoginRequest {
+  email: string
+  password: string
+}
+
+export interface RegisterRequest {
+  username: string
+  email: string
+  password: string
+}
+
+export interface CreateAlbumRequest {
+  title: string
+}
+
+export interface UpdateAlbumRequest {
+  title?: string
+  description?: string
+}
+
+// --- Storage Admin ---
+
+export interface VolumeResponse {
+  id: string
+  volume_name: string
+  uri_prefix: string
+  is_writable: boolean
+}
+
+export interface LibraryPathResponse {
+  id: string
+  volume_id: string
+  relative_path: string
+  is_ingest_destination: boolean
+}
+
+// --- Processing ---
+
+export interface JobResponse {
+  job_id: string
+  job_type: string
+  status: string
+  priority: number
+  created_at: string
+  error_message: string | null
+}
+
+export interface JobListResponse {
+  jobs: JobResponse[]
+  total: number
+}
+
+export interface BatchProgressResponse {
+  batch_id: string
+  batch_type: string
+  total: number
+  completed: number
+  failed: number
+  status: string
+  jobs: JobResponse[]
+}
+
+export interface PluginResponse {
+  plugin_id: string
+  name: string
+  plugin_type: string
+  is_enabled: boolean
+}
+
+export interface PipelineResponse {
+  pipeline_id: string
+  trigger_event: string
+  steps_count: number
+}
+
+// --- Sidecars ---
+
+export interface SidecarExportResponse {
+  asset_id: string
+  status: string
+  path: string
+}
+
+export interface DetectChangesResponse {
+  changed_count: number
+}
+
+export interface SidecarImportResponse {
+  asset_id: string
+  status: string
+}
+
+// --- Duplicates ---
+
+export interface DuplicateGroupResponse {
+  group_id: string
+  detection_method: string
+  status: string
+  candidates: DuplicateCandidateResponse[]
+}
+
+export interface DuplicateCandidateResponse {
+  asset_id: string
+  similarity_score: number
+}