Tighten web surfaces and clean handoff

crates/infinity_host_api/src/server.rs

@@ -277,6 +277,7 @@ fn handle_websocket(
     let mut sequence = 1u64;
     let mut last_event_millis = None::<u64>;
     let mut last_event_signatures = Vec::<(Option<String>, String)>::new();
+    let mut last_streamed_preview = None::<crate::dto::ApiPreviewSnapshot>;
     loop {
         let snapshot = service.snapshot();
         send_stream_message(
@@ -286,13 +287,22 @@ fn handle_websocket(
             ApiStreamMessage::Snapshot(ApiStateSnapshot::from_snapshot(&snapshot)),
         )?;
         sequence += 1;
-        send_stream_message(
-            &mut stream,
-            sequence,
-            snapshot.generated_at_millis,
-            ApiStreamMessage::Preview(crate::dto::ApiPreviewSnapshot::from_snapshot(&snapshot)),
-        )?;
-        sequence += 1;
+
+        let preview_payload = crate::dto::ApiPreviewSnapshot::from_snapshot(&snapshot);
+        if last_streamed_preview
+            .as_ref()
+            .map(|previous| previous != &preview_payload)
+            .unwrap_or(true)
+        {
+            send_stream_message(
+                &mut stream,
+                sequence,
+                snapshot.generated_at_millis,
+                ApiStreamMessage::Preview(preview_payload.clone()),
+            )?;
+            sequence += 1;
+            last_streamed_preview = Some(preview_payload);
+        }
 
         let mut new_events = snapshot
             .recent_events

crates/infinity_host_api/tests/contract.rs

@@ -147,6 +147,28 @@ fn web_ui_browser_smoke_serves_shell_assets_and_stream_bootstrap() {
     server.shutdown();
 }
 
+#[test]
+fn technical_surface_script_guards_missing_recent_events_in_state_snapshot() {
+    let server = start_server();
+    let technical_js = send_http_request(server.local_addr(), "GET", "/technical.js", None);
+    let state = send_http_request(server.local_addr(), "GET", "/api/v1/state", None);
+    let state_body: Value = serde_json::from_str(&state.body).expect("state json");
+
+    assert_eq!(technical_js.status_code, 200);
+    assert!(technical_js
+        .body
+        .contains("function snapshotRecentEvents(snapshot)"));
+    assert!(technical_js
+        .body
+        .contains("Array.isArray(snapshot?.recent_events) ? snapshot.recent_events : []"));
+    assert!(technical_js
+        .body
+        .contains("const recentEvents = snapshotRecentEvents(appState.snapshot);"));
+    assert!(state_body["state"].get("recent_events").is_none());
+
+    server.shutdown();
+}
+
 #[test]
 fn state_preview_and_snapshot_endpoints_are_versioned_and_separated() {
     let server = start_server();
@@ -268,6 +290,40 @@ fn technical_surface_commands_update_backend_node_targets_and_panel_mapping() {
     server.shutdown();
 }
 
+#[test]
+fn technical_surface_can_disable_output_again_after_enabling_it() {
+    let server = start_server();
+
+    let enable_mode = send_command_json(
+        server.local_addr(),
+        r#"{"command":{"type":"set_output_backend_mode","payload":{"mode":"ddp_wled"}}}"#,
+    );
+    let enable_output = send_command_json(
+        server.local_addr(),
+        r#"{"command":{"type":"set_live_output_enabled","payload":{"enabled":true}}}"#,
+    );
+    let disable_output = send_command_json(
+        server.local_addr(),
+        r#"{"command":{"type":"set_live_output_enabled","payload":{"enabled":false}}}"#,
+    );
+
+    assert_eq!(enable_mode.status_code, 200);
+    assert_eq!(enable_output.status_code, 200);
+    assert_eq!(disable_output.status_code, 200);
+
+    let state = send_http_request(server.local_addr(), "GET", "/api/v1/state", None);
+    let state_body: Value = serde_json::from_str(&state.body).expect("state json");
+
+    assert_eq!(state_body["state"]["technical"]["backend_mode"], "ddp_wled");
+    assert_eq!(state_body["state"]["technical"]["output_enabled"], false);
+    assert_eq!(
+        state_body["state"]["technical"]["live_status"],
+        "DDP (WLED) selected - output disabled"
+    );
+
+    server.shutdown();
+}
+
 #[test]
 fn discovery_scan_endpoint_returns_structured_results_and_rejects_invalid_subnets() {
     let server = start_server();