phase: 13_llm_page_and_decode_rate

All green. Final verification summary:

**Verified / implemented (phase 13 final pass)**
- All 4 tasks already in `complete/`; this was the verification pass. Confirmed the CSS rhythm rules (`#strip`, `#banners:empty ~ #fleet`) are served and pinned, `data/logs/NOTES-decode-spike.md` names the mechanism, and the phase-07/04 surfaces still pass their pins.
- **Found and fixed a residual defect in this phase's own code**: a stalled fetch stamps its body with the poll's *finish* time, so that sample anchors every window for the rest of the span; the jump gate "confirmed" a jump measured from that same anchor → live gufo rows 232.28 tok/s (one request at ~50) + a decaying 146/114/95 tail, repeated at 200.6. `rates.py::_publish` now requires an **independent anchor** (`_pending` stores the base sample's ts; the hold continues until it ages out). Pinned by `test_a_held_jump_is_not_confirmed_by_a_window_on_the_same_anchor` + `test_gufo_a_stale_scrape_body_never_becomes_a_rate_above_the_engine` (both fail on task 03's gate).
- Re-verified live after a dev-server restart: 10 min / 540 signed-in `/api/llm/snapshot` polls + read-only SQLite pass; **0 values > 300, 0 without a `Δ<window>` label**; 0 post-fix stored rows over the ceiling except the two pre-fix-shape rows above.

**Tests / lint (exact, all 100 % green)**
- `bash .agents/validate.sh` → **EXIT=0**; `uv run pytest --cov --cov-fail-under=94` → **1195 passed, 11 skipped, coverage 98.70 %**; `ruff check src tests agent` → All checks passed; `pyright` → 0 errors; `node --check` clean; repo hygiene clean.
- `uv run pytest -m live --live` → **11 passed / 0 failed**. `/api/health` → **all nine sources ok**.

**Completion criteria**
- Fleet/strip + head/fleet gap with screenshots (`llm-fleet-spacing{,-top,-banner-case}.png`) — met (CSS unchanged this pass, pinned on served bytes).
- Task-02 findings file names the confirmed mechanism — met.
- `test_rates.py`/`test_llm_source.py` pin label-set, both window bounds and the always-honest `Δ` — met (+2 new pins).
- Sustained watch under the recorded ceiling (300 tok/s) — met (worst 203.05, all labelled).
- Full suite + validate green; no phase-07/04 behaviour change — met.

**Documentation**
- README: `RATE_WINDOW_SECONDS` row now states the hold/confirm rule (only change needed; rest verified consistent).
- AGENTS.md: `rates.py` bullet + gap 9 rewritten (residual closed *and* the remaining sub-8× skew measured, root-caused to gap 4, explicitly not fixed by inventing a new threshold).
- **Fleet facts changed under this pass and were corrected**: operator added driveripper's bearer token → `host:driveripper`/`disks:driveripper` `ok`, live suite 9/2→11/0; but driveripper reads **identity only, zero SMART numbers** (root `smartctl` gives 55 °C/14 %; `/dev/nvme0`, `/dev/ng0n1`, `/dev/bsg/*` are root-only; its unit is `DevicePolicy=auto`, not the installer's `strict`). Evidence appended to `data/logs/NOTES-agent-install.md` + `NOTES-decode-stable.md`.

**Notable decisions / deviations**
- Did **not** add a span-relative window floor: that would re-decide task 03's pinned `MIN_WINDOW_SECONDS` and its "in-bounds diluted row publishes" test. Recorded as the next phase's call, with the root cause left at gap 4 / `14_store_performance` (the ~10 s stall).
- No live fleet change made (read-only probes + one dev-server restart). Fixtures deliberately not re-captured (no parse change, task 02 proved no shape drift). Dependency-currency advisory left untouched (no dependency moved in this phase): certifi/fastapi/starlette/websockets have newer releases.

**Next pending phase:** `.agents/phases/todo/14_store_performance` (then `15_agent_mtls`).

README.md

@@ -329,7 +329,7 @@ documentation and is never loaded, and `scripts/dev-server.sh` exports `.env.dev
 | ------------------------------------- | -------------------------------------------------------------- |
 | `HOST_TARGETS`                        | `name=url` per host running the agent; a bearer token may ride in the URL userinfo (`http://TOKEN@host:9120`) |
 | `GUFO_BASE_URL` / `VLLM_BASE_URL`     | LLM engines; unset means *not deployed here*, and its half of the page disappears |
-| `RATE_WINDOW_SECONDS`                 | the Δ window behind every measured rate — tokens/sec, bytes/sec, jiffies→CPU % (default 10); each value carries the window it actually got, and `/system`'s footnote prints that, not this default |
+| `RATE_WINDOW_SECONDS`                 | the Δ window behind every measured rate — tokens/sec, bytes/sec, jiffies→CPU % (default 10); each value carries the window it actually got, and `/system`'s footnote prints that, not this default. A window the poll loop cannot honour — the ~0.2 s catch-up after a fetch slower than the interval, or a base older than 2× the window — answers one `n/a` instead of a spike, and a rate 8× above the last one is held until a window measured from a **different** sample confirms it (phase 13) |
 | `DASH_HOST` / `DASH_PORT`             | bind address for the dashboard itself (default `127.0.0.1:8090`; the container sets `0.0.0.0`) |
 | `HOST_INTERVAL_SECONDS` / `LLM_INTERVAL_SECONDS` / `NUT_INTERVAL_SECONDS` | how often each source is polled (10 / 2 / 5 s) |
 | `DISKS_INTERVAL_SECONDS` | how often the disk-health source re-reads each agent for SMART (default 300 s — SMART is not a per-second signal). No targets of its own: the `disks:<host>` jobs exist exactly when `HOST_TARGETS` does |
@@ -502,7 +502,8 @@ auth.py ── verifier + session key, loaded once at startup (no row and no see
   healthy — the dot is reachability, and `fleet.seams` (how the two engines count prompt
   tokens differently) is a tooltip on the prompt sum rather than another line of ink. Below
   two configured engines the block is hidden: a cross-engine sum of one engine duplicates that
-  engine's panel. Below the fleet block sits the **stats strip**: one card per configured
+  engine's panel. Below the fleet block — with the page's shared `.85rem` gap, as everywhere else
+  in the section stack — sits the **stats strip**: one card per configured
   engine — reachability dot, name, age stamp, the **KV-cache bar** (the one rated cell: the
   fill and a breach's text take their colour from the payload's `severity` and nothing else),
   then `prompt tok/s` and `decode tok/s` with their provenance tag (`Δ10.0s`, scraped,