perf: skip missed ticks on all intervals, reduce scan frequency

Prevents burst of health checks, scans, and snapshots after slow
podman responses by using MissedTickBehavior::Skip. Bumps container
scan interval from 30s to 60s to reduce DB lock contention.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/archipelago/src/crash_recovery.rs

@@ -445,6 +445,7 @@ pub fn spawn_snapshot_task(data_dir: PathBuf) {
         tokio::time::sleep(std::time::Duration::from_secs(120)).await;
 
         let mut interval = tokio::time::interval(std::time::Duration::from_secs(120));
+        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
         loop {
             interval.tick().await;
             if let Err(e) = save_container_snapshot(&data_dir).await {

core/archipelago/src/health_monitor.rs

@@ -487,6 +487,8 @@ pub fn spawn_health_monitor(state: Arc<StateManager>, data_dir: PathBuf) {
         let mut mem_tracker = MemoryTracker::new();
         let mut mem_check_counter: u32 = 0;
         let mut interval = tokio::time::interval(std::time::Duration::from_secs(CHECK_INTERVAL_SECS));
+        // Skip missed ticks — prevents burst of health checks after slow podman response
+        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
 
         // Load persistent restart history and seed the in-memory tracker
         let mut restart_history = RestartHistory::load(&data_dir).await;

core/archipelago/src/monitoring/mod.rs

@@ -29,6 +29,7 @@ pub fn spawn_metrics_collector(
         tokio::time::sleep(std::time::Duration::from_secs(60)).await;
 
         let mut interval = tokio::time::interval(std::time::Duration::from_secs(300));
+        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
 
         loop {
             interval.tick().await;

core/archipelago/src/server.rs

@@ -277,9 +277,12 @@ impl Server {
                     error!("Failed to scan containers: {}", e);
                 }
 
-                // Periodic scan every 30 seconds (only broadcasts if state changed)
+                // Periodic scan every 60 seconds (only broadcasts if state changed)
                 // Uses an in-flight guard to skip scans when a previous one is still running
-                let mut interval = tokio::time::interval(Duration::from_secs(30));
+                let mut interval = tokio::time::interval(Duration::from_secs(60));
+                // Skip missed ticks instead of catching up — prevents burst of scans
+                // after a slow podman response (which causes DB lock storms)
+                interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
                 let scanning = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
                 loop {
                     interval.tick().await;