Segments Phase 3: detection algorithm, CLI, ingest hook, and efforts API

- detect.py: ActivityTrack + detect_one/detect_all (bbox pre-filter →
  start/end proximity 25m → path conformance 50m/30% → effort extraction
  with avg speed/HR/power and Coggan NP)
- cli.py: `bincio segments detect` for retroactive detection over stored
  timeseries JSONs, with optional --activity-id / --segment-id filters
- ingest.py: non-fatal hook at end of ingest_parsed runs detect_all
- server.py: GET /api/segments/{id}/efforts and POST /api/segments/{id}/detect

bincio/cli.py

@@ -20,6 +20,7 @@ from bincio.serve.cli import serve              # noqa: E402
 from bincio.dev import dev                      # noqa: E402
 from bincio.reextract_cmd import reextract_originals  # noqa: E402
 from bincio.sync_strava import sync_strava_cmd        # noqa: E402
+from bincio.segments.cli import segments_group        # noqa: E402
 
 main.add_command(extract)
 main.add_command(render)
@@ -30,3 +31,4 @@ main.add_command(serve)
 main.add_command(dev)
 main.add_command(reextract_originals)
 main.add_command(sync_strava_cmd)
+main.add_command(segments_group)