release: v0.21.0 — Thor / Series IV codec + Thor→BW adapter

Documents two commits that landed on dev since v0.20.0:

  9b71ead  series 4 codec work, initial decode success
           micromate/idf_file.read_idf_file() decodes both IDFW
           (waveform; 87-99% sample fidelity reusing
           decode_waveform_v2 at offset 0x0f1f) and IDFH (histogram;
           dedicated segment-based decoder, all 859 corpus files
           decode, 181,071 intervals total).

  9fd52dd  feat: add thor report generation, pdf generation
           micromate/idf_to_bw_report.py adapter projects parsed
           Thor data into the bw_report sidecar shape so Thor
           events flow through sfm/report_pdf.py without a
           separate renderer.  Wired into save_imported_idf.

Net effect: a Thor event ingested via /db/import/idf_file now
lands with the same fidelity as a BW event, gets a per-event PDF
on demand, and renders in Terra-View's modal chart using the same
plotting code as a BW event.

Roadmap items closed:
- Binary .IDFW / .IDFH codec (was pending)
- Series IV (Thor IDF) binary codec reverse-engineering

Companion: Terra-View v0.13.0 ships in parallel and closes Phase 1
of the SFM integration.  No API changes in seismo-relay for that
piece — Terra-View just consumes existing endpoints better.

Bumps:
- pyproject.toml 0.20.0 → 0.21.0
- minimateplus.event_file_io.TOOL_VERSION 0.20.0 → 0.21.0
  (any subsequent backfill_sidecars.py --force will re-stamp
  existing sidecars; expected + harmless)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

minimateplus/event_file_io.py

@@ -49,7 +49,7 @@ SIDECAR_KIND   = "sfm.event"
 # bumped without a `pip install` re-run — leading to confusing stale
 # version stamps in sidecars.  Bump this constant and CHANGELOG.md
 # together at release time.
-TOOL_VERSION = "0.20.0"
+TOOL_VERSION = "0.21.0"
 
 try:
     # Best-effort: prefer the installed metadata when it's NEWER than the