runGitInDir had no context: a hanging remote parked the sync goroutine in
cmd.Run(), the doSync defer never ran, `syncing` stayed true, and every manual +
periodic sync was refused with "Szinkronizálás már folyamatban" until a
controller restart. Each git command now runs under exec.CommandContext with a
fresh per-command gitCmdTimeout (120s); the deadline error names the timeout and
the (masked) git args. Debounce and failed-sync-arms-debounce unchanged.
Tests: T-C1 cancelled-context kills the subprocess promptly (red-proof: pre-fix
exec.Command shape runs to completion → test FAILS); T-C2 failed sync releases
`syncing` and a post-debounce retry EXECUTES.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6
