phase: 129_sync_chunk_progress

All green. Final report:

**Phase 129 final verification pass — 100% green** (previous work intact; this pass re-verified everything and fixed two pre-existing README inconsistencies)

- Verified on-spec: `LLMClient.embed` per-batch `on_progress` hook; importer `on_chunk_progress` plumbing (text/image/PDF branches; summary embed excluded); `SyncStatus.current_chunk/chunks_total` reset+clear contract; UI `.sync-label-chunk` pinned part with untruncated `title`/`#sync-result`
- `uv run pytest --cov=app -q`: exit 0, ~3041 passed, 0 failed, `app/` coverage **99%** (>90% gate)
- `uv run pytest tests/e2e/test_sync_chunk_progress.py -v --no-cov` (isolated, DB up): **2 passed** (endpoint chunk climb with true `chunk_document` total + UI `· chunk n/m` part)
- `uv run ruff check .`: all checks passed · `uv run pyright`: 0 errors, 0 warnings
- Completion criteria: all 5 ✅ (incl. no behavior change in completed phases — full suite green, CLI/chat no-op paths byte-identical)
- Docs: README.md fixed 2 pre-existing inconsistencies (upload section claimed "unpacks + scans immediately" — phase 90 made it unpack+register only, scan deferred to Sync; troubleshooting claimed "120s client timeout" — actual guard is the 300 s pre-token `TURN_TIMEOUT_MS`). Phase-129 label behavior already documented. AGENTS.md re-verified consistent — no changes
- Removed stray untracked `NOTES.md` (8-byte artifact); no live-infra changes; no commits — all changes left in working tree for the harness
- Next pending phase: `130_chat_answer_clusters`

frontend/assets/styles.css

@@ -2064,10 +2064,14 @@ a.answer-image:hover { text-decoration: underline; } /* flat — the caption und
    <file> (n/m)") — a long source/relative/path ellipsizes inside the
    pill; the full path lives in the button title + #sync-result (the
    aria-live announcer). Phase 128 (task 02): the label is a FLEX ROW
-   of two parts — .sync-label-main (the prefix + file/folder: min-width
+   of parts — .sync-label-main (the prefix + file/folder: min-width
    0, the shrinkable item whose ellipsis engages) + .sync-label-count
    (the pinned "(n/m)": flex 0 0 auto, NEVER clipped — the
-   .sync-result mono language, a position reads as data). */
+   .sync-result mono language, a position reads as data). Phase 129
+   (task 04): a THIRD pinned part — .sync-label-chunk (the "· chunk
+   n/m" embed-batch position of the in-flight file, the same pinned
+   mono language; hidden in every state but the import phase after
+   the file's first batch). */
 .sync-label {
   display: inline-flex;
   align-items: baseline;
@@ -2086,6 +2090,11 @@ a.answer-image:hover { text-decoration: underline; } /* flat — the caption und
   white-space: nowrap;
   font-family: var(--mono); /* the .sync-result mono language (position reads as data) */
 }
+.sync-label-chunk {
+  flex: 0 0 auto; /* NEVER clipped — the · chunk n/m position is the point (phase 129) */
+  white-space: nowrap;
+  font-family: var(--mono); /* the same pinned-part language as the count (position reads as data) */
+}
 /* Last-result announcer — soft ink, small mono */
 .sync-result {
   display: block;
@@ -5329,8 +5338,10 @@ a.answer-image:hover { text-decoration: underline; } /* flat — the caption und
      width; the History page-head already wraps the pill below its
      title block. The Sync label's min(16rem, 40vw) cap lifts and the
      label FILLS the pill (phase 128: flex 1 1 auto) — .sync-label-main
-     ellipsizes against the width left by the pinned .sync-label-count,
-     so the (n/m) stays on-screen at the right edge, never clipped;
+     ellipsizes against the width left by the pinned .sync-label-count
+     (+ the phase-129 .sync-label-chunk part while a file's embed batch
+     is in flight), so the position parts stay on-screen at the right
+     edge, never clipped;
      the refresh glyph joins its visible label. The aria-labels keep
      the accessible names. */
   .page-head-row { flex-wrap: wrap; }