feat(ai): add Codex CLI as a no-API-key AI provider for Desktop

* codex cli provider

* fixes

* mcp check

* reasoning

* simplify

* minor fixes

src-tauri/src/commands/ai.rs

@@ -44,6 +44,7 @@ pub async fn ai_stream(app: AppHandle, session_id: String, request: AiCompletion
 
 use dbx_core::agent_events::AgentEvent;
 use dbx_core::agent_loop::{run_agent_loop, AgentLoopContext};
+use dbx_core::ai_cli_agent::CliAgentCommandSpec;
 use dbx_core::models::connection::DatabaseType;
 
 #[tauri::command]
@@ -68,7 +69,18 @@ pub async fn ai_agent_stream(
     let parsed_db_type: DatabaseType =
         serde_json::from_str(&format!("\"{}\"", db_type)).map_err(|_| format!("Unknown database type: {db_type}"))?;
 
-    let agent_ctx = AgentLoopContext { state: state.inner().clone(), connection_id, database, db_type: parsed_db_type };
+    let cli_mcp_server_command = if matches!(request.config.provider, AiProvider::CodexCli) {
+        super::mcp::resolve_mcp_server_command().map(|(program, args)| CliAgentCommandSpec { program, args })
+    } else {
+        None
+    };
+    let agent_ctx = AgentLoopContext {
+        state: state.inner().clone(),
+        connection_id,
+        database,
+        db_type: parsed_db_type,
+        cli_mcp_server_command,
+    };
     let is_agent_mode = mode.as_deref() == Some("agent");
 
     let result = run_agent_loop(

src-tauri/src/commands/mcp.rs

@@ -114,6 +114,12 @@ fn installed_mcp_version() -> Option<String> {
     value.get("version")?.as_str().map(ToOwned::to_owned)
 }
 
+pub(crate) fn resolve_mcp_server_command() -> Option<(String, Vec<String>)> {
+    locate_mcp_bin()
+        .map(|path| (path, Vec::new()))
+        .or_else(|| installed_mcp_bin_script().map(|script| ("node".to_string(), vec![script])))
+}
+
 fn locate_mcp_bin() -> Option<String> {
     #[cfg(windows)]
     {
@@ -125,6 +131,12 @@ fn locate_mcp_bin() -> Option<String> {
     }
 }
 
+fn installed_mcp_bin_script() -> Option<String> {
+    let root = command_stdout("npm", &["root", "-g"]).ok()?;
+    let script = Path::new(root.trim()).join(MCP_PACKAGE_NAME).join("dist").join("index.js");
+    script.is_file().then(|| script.to_string_lossy().to_string())
+}
+
 #[cfg(windows)]
 fn locate_windows_command(command: &str) -> Option<String> {
     command_stdout("where", &[command]).ok().and_then(first_non_empty_line).or_else(|| {