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/.

app/rag/chunker.py

@@ -22,6 +22,10 @@ per-format policies:
   module preamble — imports, constants — is its own block); an oversized
   definition falls back to line packing.
 * **txt** (and any unknown suffix) — paragraph packing.
+* **container / network / volume / image / pod / kube / swap / os /
+  endpoint / j2** (A9 revised 2026-08-27) — quadlet unit files (TOML) and
+  Jinja templates; plain-text paragraph packing (``chunk_text``) — no
+  format-specific splitter (owner decision).
 
 Every format honors :data:`HARD_MAX_CHARS` (1200 — the aipi ~1024-token
 request cap) and the target/overlap settings; oversized blocks are split
@@ -331,7 +335,8 @@ def _normalize_target_overlap(target_chars: int, overlap_chars: int) -> tuple[in
     return target, min(overlap_chars, target - 1)
 
 
-#: suffix → chunker (A9, revised: md, markdown, txt, yaml, yml, json, py).
+#: suffix → chunker (A9, revised 2026-08-21 and 2026-08-27: md, markdown,
+#: txt, yaml, yml, json, py + the quadlet family and j2 — plain text).
 _FORMAT_CHUNKERS = {
     ".md": chunk_markdown,
     ".markdown": chunk_markdown,
@@ -340,6 +345,19 @@ _FORMAT_CHUNKERS = {
     ".yml": chunk_yaml,
     ".json": chunk_json,
     ".py": chunk_python,
+    # A9 revised 2026-08-27 (owner permission): the full Podman quadlet
+    # family + Jinja templates — plain-text paragraph packing, no
+    # TOML/Jinja-aware splitter (owner decision).
+    ".container": chunk_text,
+    ".network": chunk_text,
+    ".volume": chunk_text,
+    ".image": chunk_text,
+    ".pod": chunk_text,
+    ".kube": chunk_text,
+    ".swap": chunk_text,
+    ".os": chunk_text,
+    ".endpoint": chunk_text,
+    ".j2": chunk_text,
 }