fix(import): derive record_type from filename suffix instead of hardcoding "Waveform"

The BW ACH ingest path was inserting every event with
record_type="Waveform" regardless of the actual type because
read_blastware_file() had `ev.record_type = "Waveform"` hardcoded, and
the live watcher-forward path parses files from a tmp path (suffix
".bw") that doesn't carry the original extension.

V10.72+ MiniMate Plus firmware encodes the event type as the last
character of the AB0T extension scheme (H=Histogram, W=Waveform,
M=Manual, E=Event, C=Combo).  This change:

  1. Adds derive_record_type_from_filename() public helper in
     minimateplus/event_file_io.py
  2. Uses it inside read_blastware_file() so direct callers (the
     --dry-run path of scripts/import_bw.py, tests, ad-hoc scripts)
     get correct types automatically
  3. Overrides ev.record_type in WaveformStore.save_imported_bw()
     using the ORIGINAL filename (source_path.name) — required
     because the parser sees only the tmp file

Old S338 firmware (3-char extensions ending in `0`) and any
unrecognized suffix fall back to "Waveform".

Existing DB rows ingested before this fix are stuck with
record_type="Waveform" — a one-off SQL backfill would fix them
retroactively if desired.  Terra-view's event modal also derives
client-side from the filename, so the UI already shows the correct
type for old events even without the backfill.

Version bumped to 0.16.1 in pyproject.toml, event_file_io.py
TOOL_VERSION, sfm/server.py FastAPI version, and CHANGELOG.md.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CHANGELOG.md

@@ -4,6 +4,20 @@ All notable changes to seismo-relay are documented here.
 
 ---
 
+## v0.16.1 — 2026-05-14
+
+### Fixed
+
+- **`record_type` always "Waveform" for forwarded events.**  `read_blastware_file()` hardcoded `ev.record_type = "Waveform"` regardless of the file's actual type.  The watcher-forward pipeline (the main BW ACH ingest path) compounds this by parsing files from a tmp path with a `.bw` suffix, so even a filename-based fallback inside the parser still wouldn't see the original extension.  Now:
+
+  1. New `derive_record_type_from_filename(filename)` helper in `minimateplus/event_file_io.py` derives the type from the LAST character of the filename's extension (V10.72+ AB0T scheme: `H`=Histogram, `W`=Waveform, `M`=Manual, `E`=Event, `C`=Combo).  Falls back to `"Waveform"` for old S338 firmware (3-char extensions ending in `0`) and any unrecognized suffix.
+  2. `read_blastware_file()` now calls the helper with its `path.name` so direct callers (the `--dry-run` path in `scripts/import_bw.py`, tests, ad-hoc scripts) get the right value automatically.
+  3. `WaveformStore.save_imported_bw()` overrides `ev.record_type` with the **original** filename's derived type after parsing (the tmp file inside the parser doesn't carry the original extension).  This is the path the live watcher-forwarder hits, so the DB column now reflects the actual event type going forward.
+
+  Events ingested before this fix are stuck with `record_type="Waveform"` in the DB; a one-off backfill (`UPDATE events SET record_type = ... WHERE blastware_filename LIKE '%H'`) would fix them retroactively if desired.  Terra-view's event modal also derives client-side from the filename, so the UI already shows the correct type for old events even without the backfill.
+
+---
+
 ## v0.16.0 — 2026-05-11
 
 The "BW ACH ingestion" release.  When paired with **series3-watcher v1.5.0**, every Blastware ACH event (binary + `_ASCII.TXT` report) lands in SeismoDb with device-authoritative peaks, project metadata, sensor self-check, and ZC/Time-of-Peak data — without depending on the still-undecoded waveform body codec.  This is the end-to-end product win discussed in v0.15.0's "out of scope" notes: sortable / filterable monthly-summary review of historical events, populated from the BW ASCII export rather than re-decoded samples.