fix(tui): set terminal title without renaming process

[liruifengv]

Related Issue

No linked issue; this fixes terminal title updates also changing the process name.

Problem

Terminal session title updates were using process.title, so changing the terminal tab/window title also renamed the running process in system process lists.

What changed

• Route TUI terminal title updates through the pi-tui terminal API instead of process title mutation.
• Stop rewriting the process title during startup.
• Add regression coverage for session title updates, forked sessions, and startup process-name behavior.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

Test Plan

• pnpm --filter @moonshot-ai/kimi-code exec vitest run test/tui/kimi-tui-message-flow.test.ts test/cli/main.test.ts
• pnpm exec oxlint --type-aware apps/kimi-code/src/main.ts apps/kimi-code/src/tui/kimi-tui.ts apps/kimi-code/src/tui/controllers/auth-flow.ts apps/kimi-code/src/tui/controllers/session-event-handler.ts apps/kimi-code/src/tui/constant/terminal.ts apps/kimi-code/test/cli/main.test.ts apps/kimi-code/test/tui/kimi-tui-message-flow.test.ts
• pnpm --filter @moonshot-ai/kimi-code typecheck

[changeset-bot]

🦋 Changeset detected

Latest commit: 5e7761e

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@5e7761e

npx https://pkg.pr.new/@moonshot-ai/kimi-code@5e7761e

commit: 5e7761e