fix: ONVIF single-kiosk ownership + rate limiting

Server-side:
- Bundle gen: when camera event_source is "auto", first kiosk to fetch
  bundle claims ownership → writes "kiosk:<id>" to camera row. Other
  kiosks see assigned owner and skip ONVIF subscription.
- Kiosk deletion resets event_source back to "auto" so next kiosk
  takes over.
- repo.getActiveOnvifOwners() for future use.

Kiosk-side:
- Only subscribe when event_source is "auto" or "kiosk:<MY_ID>".
  Skips "kiosk:<other_id>", "server", "none", "disabled".
- Poll interval: 3s → 10s (cameras were getting overwhelmed)
- CreatePullPoint backoff: exponential 30s→60s→120s...→600s max
- Pull errors: exponential 15s→30s→45s...→300s, resubscribe after 5
  consecutive failures instead of immediately.
- load_kiosk_id() helper reads from cached bundle.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

kiosk/src/onvif_events.rs

@@ -110,25 +110,27 @@ pub fn get_statuses() -> HashMap<String, SubStatus> {
     STATUS.lock().unwrap().clone().unwrap_or_default()
 }
 
-/// Start event subscription workers for all ONVIF cameras in the bundle.
+/// Start event subscription workers for ONVIF cameras assigned to this kiosk.
-/// Idempotent — stops old workers (via ACTIVE flag) before starting new.
+/// Only subscribes when event_source is "auto" or "kiosk:<this_kiosk_id>".
 pub fn start(
     cameras: &[BundleCamera],
     cluster_key: Option<&str>,
     server_url: &str,
     kiosk_key: &str,
 ) {
-    // Only subscribe to cameras where event_source is "auto" or "kiosk:<this_id>"
+    let my_kiosk_id = crate::server::load_kiosk_id();
-    // (not "server" or another kiosk). For "auto", this kiosk subscribes because
-    // the server put the camera in this kiosk's bundle — meaning it's reachable.
     let onvif_cams: Vec<_> = cameras
         .iter()
         .filter(|c| {
             if c.cam_type != "onvif" || c.onvif_host.is_none() { return false; }
             match c.event_source.as_deref() {
-                Some("server") => false,     // server handles this one
+                Some("server") => false,
-                Some(s) if s.starts_with("kiosk:") => true,  // pinned to a kiosk (might be us)
+                Some("none") | Some("disabled") => false,
-                _ => true,                   // "auto" or missing → this kiosk subscribes
+                Some(s) if s.starts_with("kiosk:") => {
+                    let assigned = &s[6..];
+                    my_kiosk_id.as_deref() == Some(assigned)
+                }
+                _ => true, // "auto" or missing
             }
         })
         .cloned()
@@ -180,30 +182,32 @@ fn run_subscription(
     let has_pass = !pass.is_empty();
     info!("onvif-events: cam {} ({}) subscribing at {event_url} user={user} has_pass={has_pass}", cam.id, cam.name);
 
+    let mut backoff_secs: u64 = 30;
     loop {
         if generation.upgrade().is_none() {
             info!("onvif-events: cam {} generation expired, exiting", cam.id);
             return;
         }
 
-        // 1. CreatePullPointSubscription
         set_status(&cam.id, "subscribing", None);
         let sub = match create_pullpoint(&event_url, user, pass) {
             Ok(s) => s,
             Err(e) => {
-                warn!("onvif-events: cam {} CreatePullPoint failed: {e}", cam.id);
+                warn!("onvif-events: cam {} CreatePullPoint failed: {e} (backoff {backoff_secs}s)", cam.id);
                 set_status(&cam.id, "failed", Some(e));
-                std::thread::sleep(Duration::from_secs(30));
+                std::thread::sleep(Duration::from_secs(backoff_secs));
+                backoff_secs = (backoff_secs * 2).min(600);
                 continue;
             }
         };
+        backoff_secs = 30;
         info!("onvif-events: cam {} subscribed, address={}", cam.id, sub.address);
         set_status(&cam.id, "active", None);
 
-        // 2. Poll loop
+        let poll_interval = Duration::from_secs(10);
-        let poll_interval = Duration::from_secs(3);
+        let renew_interval = Duration::from_secs(55);
-        let renew_interval = Duration::from_secs(55); // renew before 60s timeout
         let mut since_renew = std::time::Instant::now();
+        let mut consecutive_errors: u32 = 0;
 
         loop {
             if generation.upgrade().is_none() {
@@ -224,16 +228,22 @@ fn run_subscription(
 
             match pull_messages(&sub.address, user, pass) {
                 Ok(events) => {
+                    consecutive_errors = 0;
                     for evt in events {
                         forward_event(server, kiosk_key, &cam.id, &evt, user, pass);
                         mark_event_received(&cam.id);
                     }
                 }
                 Err(e) => {
-                    warn!("onvif-events: cam {} pull failed: {e}", cam.id);
+                    consecutive_errors += 1;
+                    let error_backoff = (15 * consecutive_errors as u64).min(300);
+                    warn!("onvif-events: cam {} pull failed ({consecutive_errors}x): {e}, backoff {error_backoff}s", cam.id);
                     set_status(&cam.id, "failed", Some(e));
-                    std::thread::sleep(Duration::from_secs(15));
+                    if consecutive_errors >= 5 {
-                    break; // resubscribe after backoff
+                        break; // resubscribe from scratch
+                    }
+                    std::thread::sleep(Duration::from_secs(error_backoff));
+                    continue;
                 }
             }
 

kiosk/src/server.rs

@@ -162,6 +162,10 @@ pub fn load_cached_bundle() -> Option<KioskBundle> {
     }
 }
 
+pub fn load_kiosk_id() -> Option<String> {
+    load_cached_bundle().map(|b| b.kiosk_id)
+}
+
 /// Discover the BetterFrame server.
 pub fn discover_server(override_url: Option<&str>) -> String {
     if let Some(url) = override_url {

server/src/shared/bundle.ts

@@ -302,6 +302,16 @@ export async function generateBundle(
     });
   }
 
+  // ONVIF event ownership: for "auto" cameras, first kiosk to fetch bundle
+  // takes ownership. Server writes "kiosk:<id>" into event_source so
+  // subsequent kiosks see it's taken and skip.
+  for (const cam of cameras) {
+    if (cam.type === "onvif" && cam.event_source === "auto") {
+      await repo.updateCamera(cam.id, { event_source: `kiosk:${kioskId}` } as any);
+      cam.event_source = `kiosk:${kioskId}`;
+    }
+  }
+
   const bundleCameras: BundleCamera[] = [];
   for (const cam of cameras) {
     const streams = await repo.listCameraStreams(cam.id);

server/src/shared/db/repository.ts

@@ -2435,6 +2435,7 @@ export class Repository {
       await this._run(`DELETE FROM displays WHERE kiosk_id = ?`, [id]);
       await this._run(`DELETE FROM kiosk_labels WHERE kiosk_id = ?`, [id]);
       await this._run(`DELETE FROM kiosk_gpio_bindings WHERE kiosk_id = ?`, [id]);
+      await this._run(`UPDATE cameras SET event_source = 'auto' WHERE event_source = ?`, [`kiosk:${id}`]);
       await this._run(`DELETE FROM kiosks WHERE id = ?`, [id]);
     });
     for (const display of displays) {
@@ -2529,6 +2530,18 @@ export class Repository {
   // camera_event_subscriptions
   // ===========================================================================
 
+  async getActiveOnvifOwners(): Promise<Map<string, string>> {
+    const rs = await this._all<{ camera_id: string; subscribed_by_kiosk_id: string }>(
+      `SELECT DISTINCT camera_id, subscribed_by_kiosk_id FROM camera_event_subscriptions
+       WHERE subscribed_by_kiosk_id IS NOT NULL AND status = 'active'`,
+    );
+    const map = new Map<string, string>();
+    for (const r of rs) {
+      map.set(r.camera_id, r.subscribed_by_kiosk_id);
+    }
+    return map;
+  }
+
   async listEventSubscriptions(cameraId: string): Promise<CameraEventSubscription[]> {
     const rs = await this._all(
       "SELECT * FROM camera_event_subscriptions WHERE camera_id = ? ORDER BY topic",