phase: 122_image_documents

**Phase 122 (image documents) — final verification pass: all green. No code changes were needed; defects found: none.**

**Verified (implementation already complete in working tree, reviewed end-to-end):**
- Toggle (`BOR_IMAGES`/`BOR_IMAGE_EXTENSIONS`/`BOR_IMAGE_DIR`, off by default) + `GET /api/config` `images` flag
- Ingest: bytes digest, `image_dir` persistent copy, `content = summary = vision description` (chat-model call; only text embedded), fail-soft skip + `images_failed` counter
- Serve/display: `/api/documents/{id}/image` route (404 matrix), viewer `<img>` + description, Sources 48px lazy thumbnails, chat inline source figure (alt = summary), agent `read` marker
- Prune guard: images-off syncs never prune `is_image` docs

**Test / lint / coverage (exact commands & outcomes):**
- `uv run pytest` → exit 0 (green; note: pytest 9.1.1 `-q` omits the final count line in output — exit code authoritative)
- `uv run pytest --cov=app --cov-report=term-missing` → **2715 passed, exit 0, TOTAL 99%** (>90% gate)
- `uv run ruff check . && uv run pyright` → "All checks passed!" / "0 errors, 0 warnings, 0 informations"
- `uv run pytest tests/e2e/test_image_documents.py -v --no-cov` → **4 passed, exit 0** (isolation)

**Completion criteria:** (1) images=true → described/embedded/displayed docs: ✅ (E2E + integration) · (2) images=false byte-identical + image docs survive sync: ✅ (E2E negative app + unit/integration) · (3) viewer + chat rendering with alt text; failed description skips + logs, sync completes: ✅ · (4) test/lint/coverage gates: ✅ · (5) commit + phase move: deferred to harness per this pass's rules (working tree left uncommitted).

**Notable deviation (pre-existing, documented in code):** image route uses `require_user` (phase-79 posture, same gate as the document content endpoint) rather than the phase text's "public" parenthetical — matches the endpoint it mirrors.

**Next pending phase:** `123_chat_image_questions`.

tests/unit/test_importer.py

@@ -970,12 +970,14 @@ def test_import_summary_log_line_includes_summary_counters(
     """PLAN §9 summary line: the phase-30 counters sit between
     ``embed_batches`` and ``formats``; the phase-118 backfill counter
     sits between ``summary_errors`` and ``dates_updated``; the
-    phase-106 date-refresh counter sits before ``formats``."""
+    phase-106 date-refresh counter and the phase-122 ``images_failed``
+    counter sit after ``dates_updated``, before ``formats``."""
     s = ImportSummary()
     s.files, s.added, s.chunks, s.embed_batches = 3, 3, 5, 4
     s.summaries, s.summary_errors = 2, 1
     s.summary_backfilled = 1
     s.dates_updated = 0
+    s.images_failed = 0
     s.formats = {"md": 1, "yaml": 2}
     with caplog.at_level(logging.INFO, logger="app.importer"):
         s.log()
@@ -983,7 +985,7 @@ def test_import_summary_log_line_includes_summary_counters(
     assert line == (
         "import: summary files=3 added=3 updated=0 unchanged=0 pruned=0 errors=0 "
         "chunks=5 embed_batches=4 summaries=2 summary_errors=1 summary_backfilled=1 "
-        "dates_updated=0 formats=yaml:2,md:1"
+        "dates_updated=0 images_failed=0 formats=yaml:2,md:1"
     )
 
 
@@ -1103,13 +1105,17 @@ def test_no_progress_means_no_prewalk(
         excluded: frozenset[str] = EXCLUDED_DIRS,
         ignore: tuple[str, ...] = (),
         include_hidden: bool = False,
+        image_extensions: frozenset[str] = frozenset(),
     ) -> list[Path]:
         # Phase 89: the walker gained the ``ignore`` keyword; phase 105:
-        # the ``include_hidden`` flag — the sentinel accepts (and forwards)
-        # both to stay a drop-in.
+        # the ``include_hidden`` flag; phase 122: the ``image_extensions``
+        # set — the sentinel accepts (and forwards) all three to stay a
+        # drop-in.
         nonlocal walk_calls
         walk_calls += 1
-        return real_walker(r, extensions, excluded, ignore, include_hidden)
+        return real_walker(
+            r, extensions, excluded, ignore, include_hidden, image_extensions
+        )
 
     monkeypatch.setattr(importer, "iter_importable_files", counting)
     try: