feat(chat): invalidate saved chats on sources sync — versioned stamps, stale marker, Regenerate against the new index

tests/integration/test_import_docs_git.py

@@ -4,7 +4,9 @@ kind).
 
 Drives ``scripts.import_docs`` end to end with a fake ``clone_or_pull``
 (no real git, no network) and a recording fake ``import_sources`` (no
-real DB), covering:
+real DB), covering: the phase-53 version bump is stubbed in the
+``main()`` tests the same way (the ``sources_version=`` summary token
+is asserted against the canned value).
 
 - Effective sources set (phase 35: the shared resolver — stubbed here,
   keeping this file's no-real-DB style) → each git URL is cloned/pulled
@@ -83,6 +85,20 @@ def _fake_clone_factory() -> tuple[list[tuple[str, Path]], object]:
     return calls, fake_clone_or_pull
 
 
+def _stub_bump(monkeypatch: pytest.MonkeyPatch) -> list[None]:
+    """Stub the phase-53 version bump (this file keeps its no-real-DB
+    style for the counter — the fake import already avoids the KB
+    tables). Returns the call record; the canned new version is 1."""
+    bumps: list[None] = []
+
+    def fake_bump(session: object) -> int:
+        bumps.append(None)
+        return 1
+
+    monkeypatch.setattr(import_docs, "bump_sources_version", fake_bump)
+    return bumps
+
+
 # --- repo_name -------------------------------------------------------------
 
 
@@ -210,6 +226,7 @@ def test_main_git_sources_clone_then_import(
     monkeypatch.setattr(import_docs, "clone_or_pull", fake)
     fake_import = FakeImportSources()
     monkeypatch.setattr(import_docs, "import_sources", fake_import)
+    bumps = _stub_bump(monkeypatch)
 
     rc = import_docs.main([])
 
@@ -227,11 +244,19 @@ def test_main_git_sources_clone_then_import(
     for dest in (tmp_path / "bor" / "homelab", tmp_path / "bor" / "deploy"):
         assert (dest / "notes.md").is_file()
     # The final summary print reflects the import (added > 0).
-    assert "added=1" in capsys.readouterr().out
+    out = capsys.readouterr().out
+    assert "added=1" in out
+    # Phase 53: a KB-changing run bumps the sources version exactly
+    # once and reports it (stubbed — this file keeps its no-real-DB
+    # style for the counter, like the fake import above).
+    assert len(bumps) == 1
+    assert "sources_version=1" in out
 
 
 def test_main_cli_source_still_imports_manual_dir(
-    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    capsys: pytest.CaptureFixture[str],
 ) -> None:
     manual = tmp_path / "manual"
     manual.mkdir()
@@ -243,6 +268,7 @@ def test_main_cli_source_still_imports_manual_dir(
     monkeypatch.setattr(import_docs, "clone_or_pull", fake)
     fake_import = FakeImportSources()
     monkeypatch.setattr(import_docs, "import_sources", fake_import)
+    bumps = _stub_bump(monkeypatch)
 
     rc = import_docs.main(["--source", str(manual)])
 
@@ -250,6 +276,10 @@ def test_main_cli_source_still_imports_manual_dir(
     assert calls == []
     assert fake_import.calls[0]["sources"] == [manual]
     assert fake_import.calls[0]["prune"] is False
+    # Phase 53: a manual --source run that changes the KB bumps exactly
+    # once (the CLI is the other canonical sync path).
+    assert len(bumps) == 1
+    assert "sources_version=1" in capsys.readouterr().out
 
 
 def test_resolve_sources_mixed_git_and_local(