feat(mcp): implement MCP server integration for Codex CLI

- Added a new CodexConfigManager to manage TOML configuration for MCP server settings.
- Introduced MCP server IPC handlers in main.js to facilitate feature status updates.
- Enhanced CodexExecutor and FeatureExecutor to configure and utilize MCP server settings.
- Created a standalone MCP server script for JSON-RPC communication with Codex CLI.
- Updated model-provider to pass MCP server configuration to the executor.

These changes enable seamless integration of the MCP server with Codex CLI, improving feature management and execution capabilities.

app/electron/services/model-provider.js

@@ -297,6 +297,7 @@ class CodexProvider extends ModelProvider {
       systemPrompt: options.systemPrompt,
       maxTurns: options.maxTurns || 20,
       allowedTools: options.allowedTools,
+      mcpServers: options.mcpServers, // Pass MCP servers config to executor
       env: {
         ...process.env,
         OPENAI_API_KEY: process.env.OPENAI_API_KEY