Adds a new SourceAdapter that publishes the current sub-satellite point
(lon, lat, alt) plus velocity + heading for every tracked NORAD ID every
60s on subject central.sat.position.<norad_id>. Complement to v0.11.1's
satpass_predict (observer-anchored pass alerts): sat_positions is the
GLOBAL counterpart, "where is sat X right now?" rather than "when does
sat X pass over observer Y?". Neither replaces the other.
data_class=telemetry surfaces these on /telemetry, not /events (60s ticks
across ~190 sats would drown discrete-event signal). Severity 1. Geo
centroid = sub-sat point so consumers can plot the satellite directly.
Refactors satpass_predict.py to import its pure SGP4 helpers from a new
sat_common.py module (matches the wfigs_common / swpc_common precedent).
Moved: EARTH_RADIUS_KM, gmst_rad, eci_to_ecef, subsatellite_point (4
symbols, ~25 lines of pure math). Observer-specific helpers stay in
satpass_predict.py. Existing satpass_predict tests pass unchanged.
CENTRAL_SAT stream max_bytes bumped from 1 GiB to 5 GiB to accommodate
the additional ~1.9 GiB/week of position events. STREAM_CATEGORY_DOMAINS
extended from ("tle", "pass") to ("tle", "pass", "position") so the
retention sweep covers position events.
Ships disabled (enabled=false) -- celestrak_tle must be enabled and have
polled at least once for sat_positions to have TLE data to propagate.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
