phase: 187_sync_peak_memory_line

**Phase 187 — final verification pass: all criteria met, repo 100% green.**

Verified (all four tasks already in `complete/`)
- `app/core/memory.py`: `rss_mb` / `rss_peak_mb` / `cgroup_peak_mb` / `fmt_mb`, pure stdlib, never-raise, **100%** coverage, 24 branch tests.
- Lifecycle lines append-only: `sync: started … rss_mb=`, all three terminals `… rss_mb= rss_peak_mb=` (failed = sanitized one-liner beside the surviving `logger.exception`), `import: summary … rss_mb=`; prefixes byte-identical.
- `GET /api/sync/status`: additive `rss_mb`/`rss_peak_mb` (`int|null`), keyed off the ONE `_sample_rss` (run start, phase transitions, forced terminals, 5 s-throttled hook), `peak >= current` invariant, anonymous 403.
- `sources.js` `fmtSyncPeakClause`: ` · peak <N> MB` trailing the counts line / "Sync cancelled", nothing when null, no new control/live region.

Gates (exact commands)
- `uv run pytest --cov=app --cov-report=term-missing` → **4570 passed**, TOTAL **99%**, `app/api/sync.py` **100%**, `app/core/memory.py` **100%**
- `uv run ruff check .` → clean · `uv run pyright` → **0 errors**
- `uv run pytest tests/e2e/test_sync_peak_memory_visible.py -v --no-cov` → **5 passed in isolation** (ran twice)
- All 27 touched E2E families re-run **in isolation**, all green (progress_box 8, cancel 3, status_freshness 4, summary_visibility 3, sync_button 3, session_reset 4, git_freeze 2, git_log_stream_dates 5, PDF/image suites, …)

Completion criteria: every checkbox ✅ except the commit + phase-dir move, which belong to the harness.

Documentation
- README reviewed in full (pages, commands, config tables cross-checked against `app/config.py` — 85 env rows, all defaults match; phase-187 ops section, greps, process-vs-cgroup caveat): consistent, no changes needed.
- `AGENTS.md`: **fixed one pre-existing inconsistency** — rule 6 claimed the no-CDN test covers "the index page"; it actually parametrizes 10 pages (all but `/doc-edit.html`).

Notable
- Two failures early in the pass were self-inflicted by running the E2E module concurrently with the full suite on the shared Postgres (TRUNCATE deadlock + one order-dependent `test_overview` flake); both vanish under the documented serial isolation — no code defect, no change made.
- **PLAN §9 still needs the owner's reconciliation** (phase 187 adds the sync memory fields + two status keys; PLAN is never agent-edited — AGENTS rule 10 carries the spec). `TODO.md` holds an unrelated owner note, left untouched.

Next pending phase: `188_chunks_hnsw_index`.

tests/unit/test_importer.py

@@ -18,6 +18,7 @@ import base64
 import hashlib
 import logging
 import os
+import re
 import textwrap
 from collections.abc import Callable, Sequence
 from datetime import UTC, datetime
@@ -54,6 +55,11 @@ from tests.fakes import FakeEmbedder
 #: (``Settings().import_extension_set`` — now seventeen formats).
 DEFAULT_EXTS = frozenset({".md", ".markdown", ".txt", ".yaml", ".yml", ".json", ".py"})
 
+#: Phase 187 (task 02): the ONE rendering :func:`app.core.memory.fmt_mb`
+#: allows for an MB field — ``?`` when the platform cannot know, else a
+#: positive integer (never ``None``, never a float or a negative).
+MB = r"(?:\?|[1-9][0-9]*)"
+
 
 class _PoisonEmbedder(FakeEmbedder):
     """Fails (like a real endpoint) on any text containing 'poison'."""
@@ -1001,7 +1007,10 @@ def test_import_summary_log_line_includes_summary_counters(
     and the phase-151 ``pdf_images_deduped`` / ``pdf_images_blank_skipped``
     counters (the parser's per-PDF drop counts, next to
     ``pdf_pictorial_pages``) sit after ``dates_updated``, before
-    ``formats``."""
+    ``formats``. Phase 187 (task 02) APPENDS a trailing ``rss_mb=``
+    (LOCKED A2 — the memory the run sits at, ``?`` when unknowable); the
+    pre-phase text up to and including ``formats=…`` is byte-identical.
+    """
     s = ImportSummary()
     s.files, s.added, s.chunks, s.embed_batches = 3, 3, 5, 4
     s.summaries, s.summary_errors = 2, 1
@@ -1019,7 +1028,7 @@ def test_import_summary_log_line_includes_summary_counters(
     with caplog.at_level(logging.INFO, logger="app.importer"):
         s.log()
     line = caplog.records[-1].getMessage()
-    assert line == (
+    assert line.startswith(
         "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 images_failed=0 svg_indexed=4 image_context_backfilled=2 "
@@ -1027,6 +1036,9 @@ def test_import_summary_log_line_includes_summary_counters(
         "pdf_images_deduped=3 pdf_images_blank_skipped=1 "
         "formats=yaml:2,md:1"
     )
+    # Phase 187 (task 02): the ONE appended field, `?` (unknowable) or a
+    # positive integer MB — never `None`, never a negative or a float.
+    assert re.fullmatch(rf".* rss_mb={MB}", line), line
 
 
 def test_prune_removes_files_now_excluded_by_format_filter(db, tmp_path: Path) -> None:
@@ -1082,7 +1094,10 @@ def test_formats_counter_counts_extensionless_name_token(
             for r in caplog.records
             if "import: summary files=" in r.getMessage()
         )
-        assert line.endswith("formats=dockerfile:1,md:1")
+        # Phase 187 (task 02): ``formats=`` is no longer the LAST field
+        # (`` rss_mb=…`` follows), but its position and value are intact.
+        assert " formats=dockerfile:1,md:1" in line
+        assert re.search(rf"formats=dockerfile:1,md:1 rss_mb={MB}$", line), line
         assert "unknown" not in line
     finally:
         _cleanup_source(db, root.name)