Fix punctuation and paste in remote browser control

[maximus792]

Summary

• forward the browser-provided Windows virtual key code so punctuation such as . reaches CDP correctly
• leave Ctrl/Cmd+V local so the browser emits a paste event, then send its clipboard text through the existing text-input message
• keep the matching V keyup local even when Ctrl/Cmd is released first
• retain the existing server-side key-code fallback for older clients

Root cause

The computer service derived windowsVirtualKeyCode from the first character of event.key. For ., that produced 46, which Windows/CDP interprets as Delete; the correct browser key code is 190. The live screen also prevented every keydown, so Ctrl/Cmd+V could never produce a local paste event.

Verification

• bun test app/tests
• bun run --cwd app typecheck
• cd agent-computer && bun test && bun run typecheck
• bun run format:check
• bun run lint
• git diff --check
• Linux/Chromium WebSocket integration: 9/9 live-screen tests passed, including real period insertion

Fixes #424.

[davidmckayv]

Deep-reviewed against live code (correctness, governance, no vendor/secret/scale issues). Composed build+tests green. CHANGELOG/format rebase on CI-validated substance.