feat(db): zip recent events' waveform files

tests/test_db_snapshot.py

@@ -45,3 +45,37 @@ def test_snapshot_db_produces_queryable_copy(tmp_path):
     n = conn.execute("SELECT COUNT(*) FROM t").fetchone()[0]
     conn.close()
     assert n == 5
+
+
+def test_recent_waveforms_zip_bundles_all_per_event_files(tmp_path):
+    import zipfile
+    from sfm.database import SeismoDb
+    from sfm.waveform_store import WaveformStore
+    from sfm.db_snapshot import build_recent_waveforms_zip
+
+    db = SeismoDb(tmp_path / "seismo_relay.db")   # creates schema on init
+    store = WaveformStore(tmp_path / "waveforms")
+
+    def add(serial, fn, ts):
+        d = store.root / serial
+        d.mkdir(parents=True, exist_ok=True)
+        for suffix in ("", ".h5", ".a5.pkl", ".sfm.json"):
+            (d / f"{fn}{suffix}").write_bytes(b"data")
+        _seed_event(db.db_path, serial, fn, ts)
+
+    add("BE111", "AAAA1111.OE0H", "2026-06-01T00:00:00")
+    add("BE111", "BBBB2222.OE0H", "2026-06-02T00:00:00")   # newest
+
+    dest = tmp_path / "wf.zip"
+    stats = build_recent_waveforms_zip(db, store, n=1, dest_path=dest)
+
+    assert stats["events"] == 1
+    assert stats["files"] == 4
+    with zipfile.ZipFile(dest) as zf:
+        names = set(zf.namelist())
+    assert names == {
+        "BE111/BBBB2222.OE0H",
+        "BE111/BBBB2222.OE0H.h5",
+        "BE111/BBBB2222.OE0H.a5.pkl",
+        "BE111/BBBB2222.OE0H.sfm.json",
+    }