perf: migrate all user/session/auth IDs from VARCHAR(36) to native UUID

- Schema: all ~15 VARCHAR(36) columns → UUID with DEFAULT gen_random_uuid()
- Domain entities: User, Session, DeviceCode, AppPassword, Share → id: Uuid
- DTOs: CurrentUser.id → Uuid (API boundary DTOs keep String for JSON)
- Auth middleware: parse JWT claims.sub (String) → Uuid at boundary
- All repository traits, port traits, service impls updated end-to-end
- Handlers: pass Uuid by value (Copy, 16 bytes) instead of String refs
- Settings chain: updated_by column → Uuid (was text, caused setup crash)
- Removed ~650 lines of String↔Uuid conversion boilerplate
- Eliminates per-request heap allocations for ID cloning
- 16-byte binary comparison vs 36-byte string comparison in all queries
- Native UUID indexing in PostgreSQL (btree on 16 bytes vs 36-char text)

85 files changed, 1090 insertions(+), 1739 deletions(-)

src/interfaces/api/handlers/favorites_handler.rs

@@ -30,7 +30,7 @@ pub async fn get_favorites(
     State(favorites_service): State<Arc<FavoritesService>>,
     auth_user: AuthUser,
 ) -> impl IntoResponse {
-    let user_id = &auth_user.id;
+    let user_id = auth_user.id;
 
     match favorites_service.get_favorites(user_id).await {
         Ok(favorites) => {
@@ -56,7 +56,7 @@ pub async fn add_favorite(
     auth_user: AuthUser,
     Path((item_type, item_id)): Path<(String, String)>,
 ) -> impl IntoResponse {
-    let user_id = &auth_user.id;
+    let user_id = auth_user.id;
 
     // Validate item_type
     if item_type != "file" && item_type != "folder" {
@@ -99,7 +99,7 @@ pub async fn remove_favorite(
     auth_user: AuthUser,
     Path((item_type, item_id)): Path<(String, String)>,
 ) -> impl IntoResponse {
-    let user_id = &auth_user.id;
+    let user_id = auth_user.id;
 
     match favorites_service
         .remove_from_favorites(user_id, &item_id, &item_type)
@@ -143,7 +143,7 @@ pub async fn batch_add_favorites(
     auth_user: AuthUser,
     Json(body): Json<BatchFavoritesRequest>,
 ) -> impl IntoResponse {
-    let user_id = &auth_user.id;
+    let user_id = auth_user.id;
 
     if body.items.is_empty() {
         return (