Merge feat/sensor-check-h5 into dev

Sensor self-check standardized into the .h5 (schema v2, /sensor_check group),
decoded for both series-3 and series-4, plus the Thor backfill script.

CHANGELOG resolved per the convention adopted today: the incoming Unreleased
preamble was dropped rather than reconciled — no preamble under Unreleased, the
theme gets written at release time — and its load-bearing half was folded into
### Migration, which said "None" and is now false.

That block now states the real cost: .h5 schema v1 -> v2, TOOL_VERSION 0.31.0
so the standard backfill picks the traces up with no --force, and ~2 h on the
NAS. The FFT, the compliance chart and the ach_server rescue flags still owe
nothing.

The branch's rewritten "Sensor self-check — both series" entry merged cleanly
and is kept.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qcu9ByJfuKBQxmrWb8rSrN

CHANGELOG.md

@@ -46,18 +46,25 @@ All notable changes to seismo-relay are documented here.
   reference PDF. A technical breakdown of the curve is in
   `docs/ri8507_compliance_curve.md`.
 
-- **Sensor self-check waveforms decoded and drawn (`minimateplus.sensor_check`).**
-  The "Sensor Check" traces Blastware shows to the right of the waveform panel
-  live in the series-3 binary's trailing block as four length-prefixed records
-  (`0x3c`–`0x3f`) using the same delta-block codec as the main waveform:
-  Tran/Vert/Long geophone ring-downs (the transducer's damped impulse response —
-  resonant frequency + overswing/damping) and a MicL pulse train (the mic's
-  known-signal gain check). `gather_report_data` decodes them from the retained
-  BW binary at report time; the report renders them as a strip flush against the
-  waveform panel plus the **Sensor Check → Frequency / Overswing Ratio** sub-rows
-  in the stats table. Verified against the reports on all 7 oracle events (mic
-  zero-crossing frequency = 20.1 Hz exact; geophone ring-downs consistent
-  ~7.5 Hz with overswing ~3.5). Tests in `tests/test_sensor_check.py`.
+- **Sensor self-check waveforms decoded and drawn — both series.** The little
+  "Sensor Check" traces (geophone ring-downs — the transducer's damped impulse
+  response — plus a MicL pulse train, the mic's known-signal gain check) are the
+  unit's proof its sensors were healthy when it recorded the event.
+  - **Series-3** (`minimateplus.sensor_check`): four records (`0x3c`–`0x3f`) in
+    the binary's trailing block, same delta-block codec as the main waveform.
+    Verified against all 7 BE12844 reports (mic zero-crossing = 20.1 Hz exact;
+    geophone ring-downs ~7.5 Hz, overswing ~3.5).
+  - **Series-4** (`micromate.sensor_check`): the same self-test in the Thor IDFW
+    fixed header — four `01 0e 3c/3d/3e/3f` records (same channel ids) storing
+    raw int16 traces; three-channel (mic-disabled) units carry only the three
+    geophones. Validated by shape + cross-event consistency.
+  - **Standardized into the `.h5`** (`/sensor_check`, schema v2): each series'
+    decoder attaches the traces to the event at decode, the writer persists
+    them, and `gather_report_data` reads them back — so SFM renders the strip
+    (flush against the waveform panel) plus the **Sensor Check → Frequency /
+    Overswing Ratio** sub-rows without knowing the source instrument.
+  - Tests: `tests/test_sensor_check.py`, `tests/test_sensor_check_idf.py`,
+    `tests/test_event_hdf5_sensor_check.py`.
 
 - **Inspector tab in `seismo_lab.py` — annotated hex reader for series-3
   binaries (`minimateplus/binary_annotate.py`).** Tiles a raw Blastware file
@@ -77,11 +84,21 @@ All notable changes to seismo-relay are documented here.
 
 ### Migration
 
-**None.**  Every change here is additive and reads from data already on disk —
-the `.h5` samples and the retained raw BW binary.  No `.h5`/DB change, no
-schema change, no migration, no backfill, and **no `TOOL_VERSION` bump**: a
-report regenerated for an existing event simply gains the new panels, and the
-`ach_server` rescue flags don't touch the codec.
+⚠ **The sensor-check needs a backfill.**  Existing `.h5` files are schema v1
+and carry no `/sensor_check` group, so their reports show no sensor-check strip
+until regenerated.  `TOOL_VERSION` is bumped to **0.31.0**, so the standard
+backfill regenerates every event and picks up the traces with **no `--force`**:
+`scripts/backfill_thor_events.py` for series-4 (it already owed a v0.30.0 Thor
+backfill — this rides along) and the series-3 sidecar/shape backfill for
+MiniMate events.  Purely additive — no decoded value changes, and v1 `.h5`
+files read fine until then (empty strip).  DB backup first, as always.
+
+⚠ Budget **~2 h on the NAS** — ~1.5 files/sec there versus ~85/sec on the dev
+box (gzip-4 in `sfm/event_hdf5.py` against a Synology CPU).
+
+Everything else in this release owes nothing: the FFT, the USBM compliance
+chart and the `ach_server` rescue flags are additive and read data already on
+disk — no schema change, no DB migration.
 
 ---