feat(mcp): persist MCP server configurations to local data directory

- Add mcps_dir() method to AppDirs in cortex-common for cross-platform
  MCP storage directory path (Linux/macOS/Windows)
- Create new mcp_storage module in cortex-tui for MCP server config
  persistence as JSON files
- Add StoredMcpServer struct with support for stdio and HTTP transports
- Integrate storage into event_loop: save on add, remove on delete
- Load persisted MCP servers at app startup in app_runner
- Servers are stored in the platform-specific data directory:
  - Linux: ~/.local/share/cortex/mcps/
  - macOS: ~/.local/share/cortex/mcps/
  - Windows: %APPDATA%\cortex\mcps\

Author: factorydroid

cortex-common/src/dirs.rs

@@ -130,6 +130,11 @@ impl AppDirs {
         self.cache_dir.join("logs")
     }
 
+    /// Get the MCP servers directory
+    pub fn mcps_dir(&self) -> PathBuf {
+        self.data_dir.join("mcps")
+    }
+
     /// Ensure all directories exist with proper permissions
     pub fn ensure_dirs(&self) -> std::io::Result<()> {
         for dir in [&self.config_dir, &self.data_dir, &self.cache_dir] {

cortex-tui/src/lib.rs

@@ -114,6 +114,9 @@ pub mod collaboration_modes;
 // TUI capture and debugging (enabled via CORTEX_TUI_CAPTURE=1)
 pub mod capture;
 
+// MCP server storage (persistent storage for MCP configurations)
+pub mod mcp_storage;
+
 // Re-export main types
 pub use actions::{ActionContext, ActionMapper, KeyAction, KeyBinding};
 pub use app::{
@@ -163,6 +166,9 @@ pub use external_editor::{
 // TUI capture re-exports
 pub use capture::{TuiCapture, capture_enabled};
 
+// MCP storage re-exports
+pub use mcp_storage::{McpStorage, McpTransport, StoredMcpServer};
+
 // Re-export cortex-core for downstream users
 pub use cortex_engine;