chore: upgrade prettier to v3 (#644)

## Description

This PR addresses the following improvements:

**Unify Prettier Version**: Currently, the Prettier version used in
`/package.json` and `/codex-cli/package.json` are different. In this PR,
we're updating both to use Prettier v3.

- Prettier v3 introduces improved support for JavaScript and TypeScript.
(e.g. the formatting scenario shown in the image below. This is more
aligned with the TypeScript indentation standard).

<img width="1126" alt="image"
src="https://github.com/user-attachments/assets/6e237eb8-4553-4574-b336-ed9561c55370"
/>

**Add Prettier Auto-Formatting in lint-staged**: We've added a step to
automatically run prettier --write on JavaScript and TypeScript files as
part of the lint-staged process, before the ESLint checks.

- This will help ensure that all committed code is properly formatted
according to the project's Prettier configuration.

codex-cli/tests/agent-project-doc.test.ts

@@ -56,7 +56,7 @@ vi.mock("../src/approvals.js", () => {
     __esModule: true,
     alwaysApprovedCommands: new Set<string>(),
     canAutoApprove: () =>
-      ({ type: "auto-approve", runInSandbox: false } as any),
+      ({ type: "auto-approve", runInSandbox: false }) as any,
     isSafeCommand: () => null,
   };
 });
@@ -119,7 +119,7 @@ describe("AgentLoop", () => {
       approvalPolicy: { mode: "suggest" } as any,
       onItem: () => {},
       onLoading: () => {},
-      getCommandConfirmation: async () => ({ review: "yes" } as any),
+      getCommandConfirmation: async () => ({ review: "yes" }) as any,
       onLastResponseId: () => {},
     });