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

crates/api-types/src/responses.rs

@@ -6,6 +6,7 @@ pub struct UserResponse {
     pub id: Uuid,
     pub username: String,
     pub email: String,
+    pub role: String,
     pub created_at: DateTime<Utc>,
 }
 
@@ -22,6 +23,7 @@ impl UserResponse {
             id: *user.id.as_uuid(),
             username: user.username.clone(),
             email: user.email.to_string(),
+            role: user.role.clone(),
             created_at: user.created_at,
         }
     }
@@ -34,6 +36,7 @@ pub struct AlbumResponse {
     pub description: String,
     pub creator_id: Uuid,
     pub asset_count: usize,
+    pub asset_ids: Vec<Uuid>,
     pub created_at: DateTime<Utc>,
 }
 
@@ -45,6 +48,7 @@ impl AlbumResponse {
             description: album.description.clone(),
             creator_id: *album.creator_user_id.as_uuid(),
             asset_count: album.asset_count(),
+            asset_ids: album.entries.iter().map(|e| *e.asset_id.as_uuid()).collect(),
             created_at: *album.created_at.as_datetime(),
         }
     }
@@ -84,6 +88,17 @@ impl AssetResponse {
     }
 }
 
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct DateSummaryResponse {
+    pub dates: Vec<DateCountEntry>,
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct DateCountEntry {
+    pub date: String,
+    pub count: u64,
+}
+
 #[derive(Debug, serde::Serialize, utoipa::ToSchema)]
 pub struct TimelineResponse {
     pub assets: Vec<AssetResponse>,
@@ -349,6 +364,7 @@ pub struct JobResponse {
     pub status: String,
     pub priority: u32,
     pub created_at: DateTime<Utc>,
+    pub error_message: Option<String>,
 }
 
 impl JobResponse {
@@ -359,6 +375,7 @@ impl JobResponse {
             status: format!("{:?}", job.status),
             priority: job.priority,
             created_at: *job.created_at.as_datetime(),
+            error_message: job.error_message.clone(),
         }
     }
 }