fix(tui): restore exit shortcuts on plugin routes

[itz4blitz]

Issue for this PR

Closes #20069

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Plugin routes did not have a fallback app_exit handler, so Ctrl+C, Ctrl+D, and leader+q could stop working after navigating into a plugin route.

This adds a small app-level plugin-route fallback for app_exit and a regression test covering that route behavior.

How did you verify your code works?

• bun test test/cli/tui/app-exit.test.ts
• bun typecheck
• confirmed the regression test fails before the fix and passes after restoring plugin-route exit handling

Screenshots / recordings

N/A

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[YumaKakuya]

Looks like both the Linux and Windows e2e failures are stopping before the actual exit-handling behavior is exercised.

In both jobs, test:e2e:local fails in seed-e2e.ts because OPENCODE_E2E_REQUIRE_PAID=true while OPENCODE_API_KEY is unset.

So from the current CI logs, the failing checks do not seem to validate or invalidate the plugin-route exit fix itself yet.

[itz4blitz]

Looks like both the Linux and Windows e2e failures are stopping before the actual exit-handling behavior is exercised.

In both jobs, test:e2e:local fails in seed-e2e.ts because OPENCODE_E2E_REQUIRE_PAID=true while OPENCODE_API_KEY is unset.

So from the current CI logs, the failing checks do not seem to validate or invalidate the plugin-route exit fix itself yet.

Yep, that matches my read as well.

The failing e2e jobs appear to stop in seed-e2e.ts before the plugin-route exit behavior is exercised, due to OPENCODE_API_KEY being unset on the fork PR run.

Locally I verified the behavior with:

• bun test test/cli/tui/app-exit.test.ts
• bun typecheck

Happy to add more verification detail if useful.