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/search_handler.rs

@@ -60,7 +60,7 @@ impl SearchHandler {
             sort_by: params.sort_by.unwrap_or_else(|| "relevance".to_string()),
         };
 
-        match search_service.search(search_criteria, &auth_user.id).await {
+        match search_service.search(search_criteria, auth_user.id).await {
             Ok(results) => {
                 info!(
                     "Search completed in {}ms — {} files, {} folders",
@@ -101,7 +101,7 @@ impl SearchHandler {
             }
         };
 
-        match search_service.search(criteria, &auth_user.id).await {
+        match search_service.search(criteria, auth_user.id).await {
             Ok(results) => {
                 info!(
                     "Advanced search completed in {}ms — {} files, {} folders",