feat: remove startup NFO repair, update docs and tests

- Remove NFO repair scan step from ARCHITECTURE.md startup sequence
- Update CHANGELOG.md: rephrase perform_nfo_repair_scan as scheduled scan
- Add test verifying perform_nfo_repair_scan is NOT called in lifespan
- Keep existing folder scan wiring tests and unit tests intact
- NFO_GUIDE.md already correctly describes scheduled scan behavior

tests/integration/test_nfo_repair_startup.py

@@ -1,14 +1,32 @@
-"""Integration tests verifying perform_nfo_repair_scan is wired into folder scan.
+"""Integration tests verifying perform_nfo_repair_scan is wired into folder scan
+and NOT called during FastAPI lifespan startup.
 
 These tests confirm that:
 1. FolderScanService.run_folder_scan calls perform_nfo_repair_scan.
-2. Series with incomplete NFO files are queued via asyncio.create_task.
+2. perform_nfo_repair_scan is NOT imported or called in fastapi_app.py lifespan.
+3. Series with incomplete NFO files are queued via asyncio.create_task.
 """
 from unittest.mock import AsyncMock, MagicMock, call, patch
 
 import pytest
 
 
+class TestNfoRepairScanNotCalledOnStartup:
+    """Verify perform_nfo_repair_scan is NOT invoked during FastAPI lifespan startup."""
+
+    def test_perform_nfo_repair_scan_not_imported_in_lifespan(self):
+        """fastapi_app.py lifespan must not import or call perform_nfo_repair_scan."""
+        import importlib
+
+        source = importlib.util.find_spec("src.server.fastapi_app").origin
+        with open(source, "r", encoding="utf-8") as fh:
+            content = fh.read()
+
+        assert "perform_nfo_repair_scan" not in content, (
+            "perform_nfo_repair_scan must NOT be imported or called in fastapi_app.py"
+        )
+
+
 class TestNfoRepairScanCalledInFolderScan:
     """Verify perform_nfo_repair_scan is invoked from FolderScanService."""