feat: add dashboard API with quick links and widgets

- Dashboard domain with Quick Links CRUD + reorder endpoints
- Dashboard widgets management endpoints
- Database migrations for quick_links and dashboard_widgets tables
- Static file controller for Organizr widgets
- Default local user when OIDC is disabled
- Domain-based architecture refactor (src/domains/, src/shared/)
- Test suite updated for new structure (285 tests passing)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/test_dns.py

@@ -4,9 +4,9 @@ from unittest.mock import patch, MagicMock
 import dns.resolver
 import dns.exception
 
-from src.dns.service import DNSService
-from src.dns.schemas import DNSLookupRequest, DNSRecord
-from src.dns.exceptions import DNSQueryError
+from src.domains.tools.dns.service import DNSService
+from src.domains.tools.dns.schemas import DNSLookupRequest, DNSRecord
+from src.domains.tools.dns.exceptions import DNSQueryError
 
 
 @pytest.fixture