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/nextcloud/report_handler.rs

@@ -67,7 +67,7 @@ async fn handle_filter_files(
     };
 
     let favorites = fav_svc
-        .get_favorites(&user.id)
+        .get_favorites(user.id)
         .await
         .map_err(|e| AppError::internal_error(format!("Failed to get favorites: {}", e)))?;
 
@@ -179,7 +179,7 @@ async fn handle_search(
     };
 
     let results = search_svc
-        .search(criteria, &user.id)
+        .search(criteria, user.id)
         .await
         .map_err(|e| AppError::internal_error(format!("Search failed: {}", e)))?;