v0.4.1

Keep the confirm button on screen, and catch up with the reference plugin's test coverage.

• The confirmation dialog's file list is bounded and scrolls inside that bound. A recall that touched dozens of files used to render every row, grow past the viewport, and push the confirm button off screen.
• The test script clears .test-dist/ before bundling: esbuild leaves orphan bundles behind, and a deleted suite kept running against a fixture that no longer existed.
• Ported the messages-only recall, turn-boundary snapshot and transport-refusal suites from plugin-rewind, so the 0.4.0 feature set has the tests the reference implementation carries. A new guard pins the dialog's height cap.

Verified: npm run build && npm run typecheck && npm test (198/198). Published to npm as @jochenyang/dsh-rewind-plugin@0.4.1.