chore: untrack runtime state files

approved-tasks.json, dashboard/status.json, anaf-monitor/monitor.log
are auto-modified by background processes (heartbeat, cron jobs, ANAF
monitor). Untracking them stops the noisy "auto-commit from dashboard"
churn. Files stay on disk; readers (router._load_approved_tasks etc.)
already handle missing files by returning empty defaults.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -24,3 +24,8 @@ credentials/
 memory.bak/
 .use_openrouter
 .gstack/
+
+# Runtime state — auto-modified by dashboard/cron/heartbeat
+approved-tasks.json
+dashboard/status.json
+tools/anaf-monitor/monitor.log