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).

frontend/index.html

@@ -424,6 +424,48 @@
           </div>
         </div>
 
+        <!-- Phase 97 (task 04): the drill-down catalog tree — the RAG view
+             lists the KB the way the agent's `ls` sees it (the phase-94
+             concept, one end to end): the SOURCES at the top (the ONE
+             #folders-table below lists them exactly like folders — name,
+             recursive count, the stored (source, "") description), then
+             per level the subfolders (count + stored description) and the
+             level's files (the existing #docs-table further below — its
+             columns and row links are UNCHANGED; it holds the current
+             level's direct files only, hidden at the top level). #kb-crumb
+             (the location breadcrumb) and #kb-level (the current
+             directory's stored description — the block the agent's level
+             line shows) ship HIDDEN: assets/sources.js fills all three with
+             createElement + textContent (never innerHTML with
+             document-derived data). -->
+        <nav id="kb-crumb" class="kb-crumb" aria-label="Catalog location" hidden></nav>
+        <section id="kb-level" class="kb-level" aria-labelledby="kb-level-title" hidden>
+          <h2 id="kb-level-title"></h2>
+          <!-- Phase 97 (task 05): the current directory's description +
+               its Edit button (the phase-57 affordance, task 05) live in
+               the .kb-level-body — the editor swaps INSIDE it, the <h2>
+               stays put. The button ships in the static HTML (the row
+               cells build theirs); it is visible whenever the block is
+               (the description can be edited or cleared from here). -->
+          <div class="kb-level-body">
+            <p id="kb-level-summary"></p>
+            <button type="button" class="kb-summary-edit" id="kb-level-edit">Edit</button>
+          </div>
+        </section>
+        <div id="folders-wrap" class="table-wrap" role="region" aria-label="Folders" tabindex="0" hidden>
+          <table class="docs-table kb-folders-table" id="folders-table">
+            <caption class="visually-hidden">Catalog sources and folders</caption>
+            <thead>
+              <tr>
+                <th scope="col">Folder</th>
+                <th scope="col">Documents</th>
+                <th scope="col">Description</th>
+              </tr>
+            </thead>
+            <tbody id="folders-tbody"></tbody>
+          </table>
+        </div>
+
         <div class="table-wrap" role="region" aria-label="Indexed documents" tabindex="0">
           <table class="docs-table" id="docs-table">
             <caption class="visually-hidden">Indexed markdown documents</caption>