test(tui): cover permission picker table restoration

[hetaoBackend]

Change

Closing the permission mode picker on the older renderer could insert eight blank rows into an already-rendered Markdown table. The runtime fix is already merged in #333. Add a focused regression for this exact symptom using the real permission picker, inline panel host, ChatLayout, TranscriptView and MainScreen renderer; no additional runtime changes are needed.

Cover Enter and Escape at 60 and 100 columns under xterm and an ED 2 clear-to-scrollback host model. Assert exact restoration of the original buffer, contiguous table rows, cursor placement, repeated redraws and subsequent table growth.

Validation

• Pre-fix renderer: the same synthetic table replay fails with eight blank rows inside the table. Current main passes all eight new cases.
• Focused renderer/transcript suites: 173 tests passed.
• Native Apple Terminal 2.15 replay at 100 x 24: eight internal blank rows before, zero after; all 14 synthetic table records remain present.
• Full pnpm verify on clean commit 2552289f24f2dd79b936b2e6ce48590484c1e803: PASS, all 15 applicable macOS gates. The capability gate passed 4,600 tests (14 skipped).
• Performance: automatic basic suite; test-only change.
• NOT RUN: native Windows/Linux terminal acceptance or live-model interaction. Native evidence is a replay of real renderer output with synthetic data.

Publication and contribution checks

• Changes use the existing applicable licenses; no imported code or changed notices.
• Only synthetic test data; no credentials, account data, real user content, private source history or review artifacts.
• Tests extend an existing declared file; no source inventory or suite declaration changes are needed.
• No product documentation changes are needed. Offline and native replay boundaries are explicit.

Maintainer handoff

Publication scope or license changes: none.

Shared-source port: not needed for runtime behavior; optional regression-test port after review.

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