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/index.html

@@ -448,7 +448,7 @@
             <h1>Knowledge base</h1>
             <button type="button" class="sync-btn" id="sync-btn" aria-label="Sync sources" hidden>
               <svg class="sync-icon" aria-hidden="true" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.7" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12a9 9 0 1 1-9-9c2.52 0 4.93 1 6.74 2.74L21 8"/><path d="M21 3v5h-5"/></svg>
-              <span class="sync-label" id="sync-label"><span class="sync-label-main">Sync sources</span><span class="sync-label-count" hidden></span></span>
+              <span class="sync-label" id="sync-label"><span class="sync-label-main">Sync sources</span><span class="sync-label-count" hidden></span><span class="sync-label-chunk" hidden></span></span>
             </button>
           </div>
           <p class="page-sub">
@@ -460,9 +460,13 @@
         <!-- #sync-result is the aria-live announcer: the last sync
              result ("N added · …") when a sync settles, and — phase 64 —
              the LIVE file label while a sync runs ("Syncing… <file>
-             (n/m)"), UNTRUNCATED (the button's label span ellipsizes;
+             (n/m)"), UNTRUNCATED (the button's label spans ellipsize;
              screen readers hear the full source/relative path, which
-             also rides the button title). Phase 90: an in-flight upload
+             also rides the button title). Phase 129: during the import
+             phase the label gains the pinned chunk part ("· chunk n/m"
+             — the file's embed-batch position, batch granularity) and
+             the announcer/title carry it too ("Syncing… <file> (n/m)
+             · chunk n/m"). Phase 90: an in-flight upload
              run adopts the button with the BARE "Importing…" label (the
              run is unpack + register only — no scan, so its status
              never carries a file or counts). After an upload settles it