phase: 97_kb_tree_catalog

All completion criteria verified — everything is green, no defects found. Final report:

## Phase 97 final verification pass — ALL GREEN

**Verified (no code changes needed):**
- `GET /api/docs/tree` (admin), `build_kb_tree` pure builder, `PATCH /api/folders/summary`, migration 0018 (`manually_edited`, head confirmed), generator skip/keep + `kept_manual` stat, RAG tree UI + edit affordance in `sources.js`/`index.html`/`styles.css`
- `tests/e2e/test_kb_tree.py`: 8 passed — top level, drill source/folder, edit round-trip, clear, manual-desc-survives-sync, reload fallback, anonymous gate
- Integration: tree shape/order/403/empty/indexed-only + PATCH update/create/root/clear/404/403/no-LLM + stat-walk equivalence (in `test_docs_api.py`); 3-field `folder_summaries=` import token preserved

**Gates (exact commands):**
- `uv run pytest --cov=app --cov-report=term-missing` → **2053 passed**, TOTAL coverage **99%** (>90% ✓)
- `uv run ruff check . && uv run pyright` → **All checks passed / 0 errors**
- `uv run pytest tests/e2e/test_kb_tree.py -v --no-cov` → **8 passed** in isolation
- 30 story/RAG-view E2E suites run **one per process**: all passed, incl. `test_ls_tree_drilldown` (agent `ls` byte-identical ✓), `test_import_documents`, `test_edit_summaries`, `test_admin_auth`, `test_kb_overview`

**Completion criteria:** tree view ✓ · edit round-trip + clear ✓ · manual persists/clear resets ✓ · `ls` unchanged ✓ · pytest/coverage/lint ✓ · E2E isolation ✓ · commit — left to harness per protocol (working tree untouched, `git add/commit` not run)

**Deviations:** none. **Next pending phase:** none — `todo/` contains only 97 (96 already committed).

tests/e2e/test_sticky_navbar.py

@@ -214,7 +214,14 @@ def test_app_header_stuck_at_top_on_sources(
 ) -> None:
     page.set_default_timeout(30_000)
     login(page, app_url)  # → /sources.html (the table is admin-only)
-    expect(page.locator("#docs-tbody tr")).to_have_count(TOTAL_DOCS)
+    # Phase 97: the catalog is the drill-down tree — the top level
+    # lists the two sources (the KB total rides the stat cards; the
+    # flat 55-row tbody no longer exists). The LONG page the story
+    # needs is a file level: drill into `gen` (41 direct docs).
+    page.locator("#folders-tbody .folder-link").first.wait_for(state="visible")
+    expect(page.locator("#stat-docs")).to_have_text(str(TOTAL_DOCS))
+    page.click('#folders-tbody a.folder-link:text-is("gen")')
+    expect(page.locator("#docs-tbody tr")).to_have_count(TOTAL_DOCS - 13)
 
     # The precondition the story needs: the page must actually scroll —
     # fail loudly if the table ever stops being long enough.