phase: 188_chunks_hnsw_index

**Phase 188 — final verification pass: all criteria green.**

- **Verified (all 5 tasks already in `complete/`)**: migration `0029` (`CONCURRENTLY` in an autocommit block, INVALID pre-drop, post-validate, tested downgrade) — manual `alembic downgrade -1` → index absent, `upgrade head` → `indisvalid = t` (72 kB); `retrieval_ef_search` = **400** with `SET LOCAL` + clamp-and-WARN in `_vector_candidates`; CATALOG group *"Retrieval & honesty"*; D5 runbook in README.
- `uv run pytest --cov-reset` then `uv run pytest tests/unit tests/integration -q --cov=app --cov-report=term-missing` → **exit 0, TOTAL 99 %** (6 946 stmts / 16 miss) — gate >90 % met. (A stale `.coverage` left by an earlier session produced a spurious 90.00 %/3-failure reading; `--cov-reset` cleared it.)
- `uv run pytest tests/e2e/test_vector_index_recall.py -v --no-cov` → **4 passed in isolation**; retrieval/chat/recall neighbours (`test_retrieval_quality`, `test_chat_rag`, `test_search_recall_small_sources`) → exit 0.
- `uv run ruff check .` → **All checks passed**; `uv run pyright` (whole repo) → **0 errors**.
- **Completion criteria**: 0029 DDL + tested downgrade ✅ · ef_search SET LOCAL/clamp/negative-refusal/CATALOG/.env.example/README ✅ (400 everywhere, no stale 100/150 pins) · plan pin + deterministic recall pin (≥0.99 @400, cosine ≤1e-6, monotonicity, vacuity guard) ✅ · live battery off/on recorded (`benchmarks/phase188_live_gate/task05_battery_index_{off,on}.txt` byte-identical, `deterministic_gate_recall.txt`, build 161 s / 1 625 MB / 81 MB RSS, phase report `.agents/reports/188_chunks_hnsw_index/`) ✅ · pytest/coverage/ruff/pyright ✅ · phase E2E ✅ · docs ✅ · commit left to the harness.
- **Documentation**: reviewed README + AGENTS end-to-end — all 85 `Settings` fields documented in README *and* `.env.example`, every path referenced by both docs exists (0 broken), `BOR_SETTINGS_DB` real, `BOR_THEME` correctly described as retired, runbook matches the measured `/dev/shm` = 63 MB finding, ef_search default consistent → **verified consistent, no changes needed**.
- **Notable**: built and ran a temporary offline synthetic recall gate (`--docs 1000`, 8 000 chunks) to re-check A7 without an endpoint; on near-orthogonal synthetic vectors exact parity only arrives at `ef_search ≈ 700` (400 → 0.91), which is a property of that corpus distribution, not of the index — exactly the counter-case already recorded in `tests/integration/test_chunks_hnsw_recall.py`. Because a synthetic corpus can't be calibrated to the real embedding cone without the endpoint, I **deleted the script** rather than ship a verdict that could be misread as production. `AIPI_KEY` is absent in this environment (and `100.117.2.24:1219` /embeddings times out), so the live battery could not be re-run — its recorded task-04/05 captures stand. Scratch DB `brain_of_reese_hnswgate` dropped; repo left clean.
- **Next pending phase**: `189_chat_save_long_turns`.

tests/fixtures/hnswkb/infra/ntfy-relay.md

@@ -0,0 +1,15 @@
+# Ntfy relay
+
+The ntfy relay runs on `notify-host-1` and fans alert payloads out to the
+phones and the desktop notifier.
+
+- Topic namespaces are per host, so a host can only publish into its own.
+- Retention is twelve hours; anything older is dropped on the sweep.
+- The access log lives at `/var/log/ntfy/access.log` and rotates weekly.
+- SMTP fallback is disabled on purpose: a failed push is a signal, not
+  something to paper over with an email.
+- The relay is fronted by the proxy on 443 with mutual TLS for publishers.
+
+Publishing is a plain POST with the topic in the path. The relay stamps a
+monotonic sequence number so a subscriber can detect a gap after a
+reconnect, and the gap detection is what the shelf watchdog polls.

tests/fixtures/hnswkb/infra/tilecache.md

@@ -0,0 +1,35 @@
+# Tilecache
+
+Tilecache serves the vector tiles for the map boxes from `map-host-2`,
+listening on port 8077 behind the reverse proxy. Everything below is the
+shape of that cache on the shelf, not a general tile server guide.
+
+## Cache budget and eviction
+
+The cache budget is 40 GiB on the nvme. The eviction watermark sits at 88
+percent of that budget: once the cache crosses the watermark, tilecache
+evicts the coldest tiles until it drops back under it.
+
+Raise the eviction watermark so the hot zoom levels stay pinned through a
+bulk re-render:
+
+1. `tilecache config set eviction-watermark 92`
+2. `tilecache config set pin-zoom-floor 12`
+3. `systemctl restart tilecache`
+
+Zoom levels 12 to 15 are the hot set for the atlas layers, and the pin
+floor keeps them resident while the watermark holds. Zoom 16 and above is
+rendered on demand and is always evictable.
+
+## Origin fetches
+
+Origin fetches go to `origin.maps.internal`, and a slow origin reply is
+treated as a miss after 900 ms. A stale origin reply keeps the previous
+tile pinned rather than evicting the hot zoom set, so a watermark raise is
+safe during a bulk re-render.
+
+## Watermark maths
+
+At a 40 GiB budget the 88 percent watermark means eviction starts at 35.2
+GiB. The 92 percent setting moves that to 36.8 GiB, which buys roughly one
+extra render pass of zoom 14 before anything cold is dropped.

tests/fixtures/hnswkb/infra/wireguard-hub.md

@@ -0,0 +1,15 @@
+# Wireguard hub
+
+The Wireguard hub on `edge-host-1` is the only way into the shelf from a
+laptop. Each device gets one peer entry and one allowed-IPs line.
+
+- Listen port 51820/udp, one peer per device.
+- Allowed IPs are per-device /32s; the hub does not advertise the LAN.
+- Persistent keepalive is 25 seconds for the roaming peers.
+- Key rotation is a manual ceremony: generate, swap the peer file, reload.
+- The hub hands out addresses from 10.66.0.0/24, one /32 per peer.
+
+A peer that roams between the mobile network and wifi must keep the same
+endpoint or the hub drops the stale mapping after the keepalive window.
+The routing table is re-read on a reload, so a swapped peer file needs no
+reboot of the host.