F-04: rename gps_health() response fields per tester feedback: - total_tracks → tracks_total - by_activity → tracks_by_activity - recent_pipeline_runs (list) → last_pipeline_run (object | null) Change LIMIT from 10 to 1; fetch single row instead of a list. F-05: rewrite _findGpsInsertPosition with explicit priority order: 1. gpx-layer-* (ET-006 GPX file layers) — highest priority 2. route-* (ET-002 routing layers) Remove old combined find() that lacked clear priority semantics. Add tests/web/gps_tracks.test.js (22 JS unit tests via node:test): - _findGpsInsertPosition priority logic (9 cases) - Filter state management — default state assertions (5 cases) - Color palette mapping and _buildColorExpression (8 cases) Add tests/web/test_gps_tracks.py — Python pytest runner (8 static checks + node --test invocation). Refs: ET-008 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
