fix: merge main (v0.161.0) into classification feature branch

Resolve all 40 merge conflicts from merging origin/main into the
classification feature branch. Key resolutions:

- Auto-generated files (BUILD_DATE, VERSION, etc.): use main's version
- API tokens: take main's version (token expiry, reactivation, hard-delete)
- Auth: take main's Dropbox credential sharing + token expiry checking
- Config: take main's social_auth_dropbox_use_global_credentials option
- Files API: take main's improved duplicate handling + rate limiting
- Models: keep ClassificationRuleModel alongside main's new models
- Mobile: take main's mature implementation
- Templates/translations: take main's versions (device deletion, reactivation keys)
- Migration: renumber 038_add_classification_rules → 039_add_classification_rules
  to chain after main's 038_add_api_token_expires_at
- Requirements: take main's version (adds segno QR library)
- Tests: take main's more complete token tests, keep classification imports

tests/conftest.py

@@ -116,6 +116,7 @@ def client(db_session) -> TestClient:
 
     # Import the canonical get_db function
     from app.database import get_db
+    from app.middleware.upload_rate_limit import require_upload_rate_limit
 
     # Override the get_db dependency to use our test database
     def override_get_db():
@@ -127,6 +128,14 @@ def client(db_session) -> TestClient:
     # Override the single canonical get_db dependency
     fastapi_app.dependency_overrides[get_db] = override_get_db
 
+    # Disable per-user upload rate limiting in tests so that upload-heavy
+    # test suites are not rejected with 429 Too Many Requests.
+    async def _no_rate_limit() -> None:
+        """No-op override: skip upload rate limiting during tests."""
+        return None
+
+    fastapi_app.dependency_overrides[require_upload_rate_limit] = _no_rate_limit
+
     # Use base_url to satisfy TrustedHostMiddleware
     with TestClient(fastapi_app, base_url="http://localhost") as test_client:
         yield test_client