chore(release): v0.22.0

Full-snapshot bundle (SFM side): document the /db/snapshot,
/db/waveforms/recent.zip and gated /db/restore endpoints. Bump package
version 0.21.1 -> 0.22.0 (pyproject), README version badge + history, and
CHANGELOG. TOOL_VERSION (codec/output provenance) left at 0.21.1 on purpose
— the event codec is unchanged, so existing sidecars must not be flagged
stale for re-backfill.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WyT5m9xppYmoVGmCCVVV6X

README.md

@@ -1,4 +1,4 @@
-# seismo-relay  `v0.21.0`
+# seismo-relay  `v0.22.0`
 
 A ground-up replacement for **Blastware** — Instantel's aging Windows-only
 software for managing seismographs.  Supports both the **MiniMate Plus
@@ -54,6 +54,11 @@ over direct RS-232 or cellular modem (Sierra Wireless RV50 / RV55).
 > flow through the existing Event Report PDF pipeline without a
 > separate renderer.  Terra-View v0.13.0 ships in parallel and
 > closes Phase 1 of the SFM integration — see its CHANGELOG.
+> **v0.22.0 (2026-07-03)** adds the SFM side of the full-snapshot
+> bundle: `GET /db/snapshot` (WAL-safe DB copy), `GET /db/waveforms/
+> recent.zip` (recent events' waveform files), and a gated
+> `POST /db/restore` (`SFM_DB_RESTORE_ENABLED`, dev-only).  Terra-View
+> v0.17.0 drives them to pull a one-pass prod→dev refresh.
 > See [CHANGELOG.md](CHANGELOG.md) for full version history.
 
 ---
@@ -210,6 +215,18 @@ optionally paired with their ASCII sidecar reports; both dedup by
 | `POST` | `/db/import/blastware_file` | Series III: `.AB0*` / `.N00` binaries + paired `_ASCII.TXT`.  Source: `series3-watcher`. |
 | `POST` | `/db/import/idf_file` | Series IV: `.IDFH` / `.IDFW` binaries + paired `.IDFW.txt` / `.IDFH.txt`.  Source: `thor-watcher`. |
 
+### DB snapshot / restore endpoints
+
+Back the "full snapshot bundle" prod→dev refresh Terra-View orchestrates
+(Settings → Database).  Snapshot/zip are read-only; restore is gated and
+dev-only.
+
+| Method | URL | Description |
+|--------|-----|-------------|
+| `GET` | `/db/snapshot` | WAL-safe point-in-time copy of `seismo_relay.db` via the SQLite online backup API. |
+| `GET` | `/db/waveforms/recent.zip?n=…` | Zips the on-disk files (event file + `.h5` / sidecars) for the *n* most-recent events. |
+| `POST` | `/db/restore` | Validate-first restore of an uploaded DB + waveforms; takes a WAL-safe pre-restore safety backup, path-traversal-guards the zip.  Gated by `SFM_DB_RESTORE_ENABLED` (dormant → 404). |
+
 ---
 
 ## minimateplus library