refactor(map): extract RF tool hooks; scan panel polish

[SimmerV]

Summary

• Split Map.tsx (4579 → 2573 lines) by extracting LOS/scan/coverage state and compute effects into 10 colocated hooks in pages/map/ (useLosState, useScanState, useCoverageState, useCoverageMergeOrigins, useUrlMapSync, useLosCompute, useScanCompute, useCoverageCompute), plus pure helpers in helpers.ts and the GeoJSON/KML export in coverageExport.ts. Behavior unchanged.
• Scan panel no longer auto-minimizes after the first result; user can still minimize manually.
• Truncated scan header text ("From {origin} · N reachable / M") now has a native title tooltip with the full string.