feat: add configurable sandbox mode setting

Add a global setting to enable/disable sandbox mode for Claude Agent SDK.
This allows users to control sandbox behavior based on their authentication
setup and system compatibility.

Changes:
- Add enableSandboxMode to GlobalSettings (default: true)
- Add sandbox mode checkbox in Claude settings UI
- Wire up setting through app store and settings service
- Update createChatOptions and createAutoModeOptions to use setting
- Add getEnableSandboxModeSetting helper function
- Remove hardcoded sandbox configuration from ClaudeProvider
- Add detailed logging throughout agent execution flow

The sandbox mode requires API key or OAuth token authentication. Users
experiencing issues with CLI-only auth can disable it in settings.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/server/src/routes/agent/routes/send.ts

@@ -19,7 +19,16 @@ export function createSendHandler(agentService: AgentService) {
         model?: string;
       };
 
+      console.log('[Send Handler] Received request:', {
+        sessionId,
+        messageLength: message?.length,
+        workingDirectory,
+        imageCount: imagePaths?.length || 0,
+        model,
+      });
+
       if (!sessionId || !message) {
+        console.log('[Send Handler] ERROR: Validation failed - missing sessionId or message');
         res.status(400).json({
           success: false,
           error: 'sessionId and message are required',
@@ -27,6 +36,8 @@ export function createSendHandler(agentService: AgentService) {
         return;
       }
 
+      console.log('[Send Handler] Validation passed, calling agentService.sendMessage()');
+
       // Start the message processing (don't await - it streams via WebSocket)
       agentService
         .sendMessage({
@@ -37,12 +48,16 @@ export function createSendHandler(agentService: AgentService) {
           model,
         })
         .catch((error) => {
+          console.error('[Send Handler] ERROR: Background error in sendMessage():', error);
           logError(error, 'Send message failed (background)');
         });
 
+      console.log('[Send Handler] Returning immediate response to client');
+
       // Return immediately - responses come via WebSocket
       res.json({ success: true, message: 'Message sent' });
     } catch (error) {
+      console.error('[Send Handler] ERROR: Synchronous error:', error);
       logError(error, 'Send message failed');
       res.status(500).json({ success: false, error: getErrorMessage(error) });
     }