feat: add session resume capability via 'codex resume' command

close #51

cli/src/codex/loop.ts

@@ -26,6 +26,7 @@ interface LoopOptions {
     codexArgs?: string[];
     codexCliOverrides?: CodexCliOverrides;
     permissionMode?: PermissionMode;
+    resumeSessionId?: string;
     onSessionReady?: (session: CodexSession) => void;
 }
 
@@ -37,7 +38,7 @@ export async function loop(opts: LoopOptions): Promise<void> {
         api: opts.api,
         client: opts.session,
         path: opts.path,
-        sessionId: null,
+        sessionId: opts.resumeSessionId ?? null,
         logPath,
         messageQueue: opts.messageQueue,
         onModeChange: opts.onModeChange,