feat(import): index quadlet unit files and jinja templates (A9 revision)

Phase 47 (owner permission 2026-08-27, TODO.md L10–11, roadmap R1): the
full Podman quadlet family (.container, .network, .volume, .image,
.pod, .kube, .swap, .os, .endpoint) and .j2 Jinja templates join the
allowed + default A9 import formats, chunked as plain text (owner
decision — no TOML/Jinja-aware splitter). No env configuration needed:
a default import now indexes them.

- app/config.py: _ALLOWED_IMPORT_EXTENSIONS + the default
  import_extensions CSV gain the ten names (the original seven first);
  the never-widen BOR_IMPORT_EXTENSIONS validator is untouched and
  still rejects truly unknown extensions.
- app/rag/chunker.py: ten _FORMAT_CHUNKERS entries -> chunk_text
  (HARD_MAX_CHARS 1200 honored, unknown-suffix fallback unchanged);
  docstring/comments cite the A9 revision 2026-08-27.
- tests/fixtures/docs/homelab/: quadlet/compose.container (realistic
  quadlet TOML, >1500 chars, [Unit]/[Service]/[Container] sections,
  RESE-QUADLET-SENTINEL-77aa), quadlet/lan.network,
  quadlet/cache.volume, templates/deploy.j2 (for/set/if Jinja
  constructs + RESE-JINJA-SENTINEL-33dd). Every suite that seeds the
  fixture tree updates its 9 -> 13 document-count constants.
- tests/unit/test_config.py: allowed set carries all seventeen formats,
  default CSV + dotted import_extension_set include the ten, the
  validator accepts the new names and still rejects unknowns.
- tests/unit/test_chunker.py: dispatch parity with chunk_text for every
  new suffix (parametrized), the .container fixture chunks >=2 under
  the cap with the sentinel surviving, the .j2 fixture keeps {{ }}
  verbatim, the unknown-suffix fallback is unchanged.
- tests/unit/test_importer.py: a default-extensions walk over a temp
  tree indexes exactly the ten new files (unknown/hidden/excluded
  filtered), the original seven still walk, stem-title fallback holds.
- tests/integration/test_import_quadlet_jinja.py (new): import_sources
  over a temp tree with .container/.volume/.j2 -> documents + chunks
  rows with stem titles; delta re-import updates only the changed .j2
  doc; prune drops the deleted .volume doc with cascade.
- tests/e2e/test_quadlet_jinja_import.py (new, story suite, mock-only,
  isolation): GET /api/docs (admin session) lists the four new-format
  docs with non-zero chunk counts and stem titles; the Sources table
  renders a row + .doc-link per file; the phase-26 modal shows the
  .container TOML ([Container] section + sentinel) with stem title and
  the container format badge; a RESE-JINJA-SENTINEL-33dd question
  FTS-matches the .j2 chunk -> honest-positive (A8: LOW requires zero
  FTS hits) — the bubble is not .is-deflected and a source chip names
  templates/deploy.j2.
- README.md + .env.example: the extended default format set (A9
  revised 2026-08-27, plain-text chunking, narrow-only rule intact).
- .agent/PLAN.md: the A9 revision (owner-locked R1) — A9 row status,
  the revision note under the anchors table, and the §5 chunking-policy
  + §11 workflow lines. The only PLAN edit this phase.

Gates: uv run pytest 795 passed; app/ coverage TOTAL 99% (>90%);
ruff check + pyright clean; story E2E 4/4 in isolation (DB up);
regression E2E suites test_import_documents (3) / test_sync_button
(3) / test_git_sources_admin (6) green in isolation.

Also records the 47_quadlet_jinja_import task-file moves (01–03)
todo/ -> complete/.

tests/e2e/test_retrieval_quality.py

@@ -84,13 +84,17 @@ def _ask(page: Page, message: str) -> None:
 def test_multi_format_import_hidden_doc_excluded(
     page: Page, app_url: str, mock_llm: int, db_ready: None
 ) -> None:
-    """A9 (revised): all seven formats import; hidden (dot) paths never do."""
+    """A9 (revised): all seventeen formats import; hidden (dot) paths never do."""
     summary = _reset_db(mock_llm, seed=True)
     assert summary is not None
-    # Nine A9-format fixture files (phase 44 added homelab/tables.md);
-    # .hidden/junk.md must never be walked.
-    assert summary.added == 9
-    assert summary.formats == {"md": 5, "yaml": 1, "json": 1, "py": 1, "txt": 1}
+    # Thirteen A9-format fixture files (phase 44 added homelab/tables.md,
+    # phase 47 added the quadlet + j2 fixtures); .hidden/junk.md must never
+    # be walked.
+    assert summary.added == 13
+    assert summary.formats == {
+        "md": 5, "yaml": 1, "json": 1, "py": 1, "txt": 1,
+        "container": 1, "network": 1, "volume": 1, "j2": 1,  # phase 47
+    }
 
     # Phase 16: the catalog is admin-only — perform the real form login,
     # then call the API with the signed cookie the browser now holds.
@@ -103,7 +107,7 @@ def test_multi_format_import_hidden_doc_excluded(
     r = httpx.get(f"{app_url}/api/docs", timeout=10, cookies=cookies)
     assert r.status_code == 200
     docs = r.json()["documents"]
-    assert len(docs) == 9
+    assert len(docs) == 13
     assert all(".hidden" not in d["path"] for d in docs)
     assert {d["path"] for d in docs} >= {
         "homelab/container_gitlab/gitlab.md",
@@ -114,7 +118,7 @@ def test_multi_format_import_hidden_doc_excluded(
     }
 
     # The Sources page (we're already on it, signed in) reflects the set.
-    expect(page.locator("#stat-docs")).to_have_text("9")
+    expect(page.locator("#stat-docs")).to_have_text("13")
     expect(page.locator("#docs-tbody tr", has_text=".hidden")).to_have_count(0)