fix: Implement Phase 2 major fixes

Database:
- Add missing indexes for api_key_hash, status, metrics queries
- New migration: 005_add_missing_indexes.sql

Server:
- Fix WebSocket Ping/Pong protocol (RFC 6455 compliance)
- Use separate channel for Pong responses

Agent:
- Replace format!() path construction with PathBuf::join()
- Replace todo!() macros with proper errors for macOS support

Dashboard:
- Fix duplicate filter values in Agents page (__unassigned__ sentinel)
- Add onError handlers to all mutations in Agents, Clients, Sites pages

All changes reviewed and approved.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

projects/msp-tools/guru-rmm/server/src/ws/mod.rs

@@ -7,7 +7,6 @@
 //! - Watchdog event handling
 
 use std::collections::HashMap;
-use std::sync::Arc;
 
 use axum::{
     extract::{
@@ -18,7 +17,7 @@ use axum::{
 };
 use futures_util::{SinkExt, StreamExt};
 use serde::{Deserialize, Serialize};
-use tokio::sync::{mpsc, RwLock};
+use tokio::sync::mpsc;
 use tracing::{debug, error, info, warn};
 use uuid::Uuid;
 
@@ -253,9 +252,13 @@ pub async fn ws_handler(ws: WebSocketUpgrade, State(state): State<AppState>) ->
 async fn handle_socket(socket: WebSocket, state: AppState) {
     let (mut sender, mut receiver) = socket.split();
 
-    // Create channel for outgoing messages
+    // Create channel for outgoing protocol messages (ServerMessage)
     let (tx, mut rx) = mpsc::channel::<ServerMessage>(100);
 
+    // Create separate channel for raw WebSocket frames (Pong responses)
+    // This allows proper WebSocket protocol compliance without changing the public API
+    let (pong_tx, mut pong_rx) = mpsc::channel::<Vec<u8>>(16);
+
     // Wait for authentication message
     let auth_result = match authenticate(&mut receiver, &mut sender, &state).await {
         Ok(result) => {
@@ -358,12 +361,26 @@ async fn handle_socket(socket: WebSocket, state: AppState) {
     let agent_id = auth_result.agent_id;
 
     // Spawn task to forward outgoing messages
+    // Handles both protocol messages (ServerMessage) and raw Pong frames
     let send_task = tokio::spawn(async move {
-        while let Some(msg) = rx.recv().await {
-            if let Ok(json) = serde_json::to_string(&msg) {
-                if sender.send(Message::Text(json)).await.is_err() {
-                    break;
+        loop {
+            tokio::select! {
+                // Handle protocol messages (ServerMessage -> JSON text)
+                Some(msg) = rx.recv() => {
+                    if let Ok(json) = serde_json::to_string(&msg) {
+                        if sender.send(Message::Text(json)).await.is_err() {
+                            break;
+                        }
+                    }
                 }
+                // Handle Pong responses (WebSocket protocol compliance)
+                Some(data) = pong_rx.recv() => {
+                    if sender.send(Message::Pong(data)).await.is_err() {
+                        break;
+                    }
+                }
+                // Both channels closed
+                else => break,
             }
         }
     });
@@ -377,11 +394,10 @@ async fn handle_socket(socket: WebSocket, state: AppState) {
                 }
             }
             Ok(Message::Ping(data)) => {
-                if tx
-                    .send(ServerMessage::Ack { message_id: None })
-                    .await
-                    .is_err()
-                {
+                // WebSocket protocol requires Pong response with same payload
+                // Send via pong channel to the send task
+                if pong_tx.send(data).await.is_err() {
+                    warn!("Failed to send Pong response for agent {}", agent_id);
                     break;
                 }
             }