feat(api): standardize REST contracts and auth

app/auth/metadata_dependencies.py

@@ -61,7 +61,7 @@ async def get_current_metadata_user(
         )
         raise HTTPException(
             status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-            detail=f"Metadata database error: {exc}",
+            detail="Metadata database is unavailable",
         ) from exc
     if not user or not user.is_active:
         raise HTTPException(
@@ -80,7 +80,7 @@ async def get_current_metadata_user(
         )
         raise HTTPException(
             status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-            detail=f"Metadata database error: {exc}",
+            detail="Metadata database is unavailable",
         ) from exc
     return user
 

app/auth/project_dependencies.py

@@ -78,7 +78,7 @@ async def resolve_project_context(
         )
         raise HTTPException(
             status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-            detail=f"Metadata database error: {exc}",
+            detail="Metadata database is unavailable",
         ) from exc
 
     return ProjectContext(