feat(app): support renaming agent and terminal tabs

[biggameking]

Summary

• Add a Rename action for Agent and Terminal tabs in desktop and mobile tab menus.
• Persist custom tab labels per workspace in the workspace layout store.
• Resolve tab presentation labels from persisted overrides, including split-pane tab rows.
• Add unit tests for menu rename entries and tab label persistence behavior.

Validation

• npm run test --workspace=@getpaseo/app -- src/screens/workspace/workspace-tab-menu.test.ts src/stores/workspace-layout-store.test.ts
• npm run build:workspace-deps --workspace=@getpaseo/app
• npm run typecheck --workspace=@getpaseo/app