Internationalization (i18n) support, keyboard input handling, integrated terminal functionality.

# Cannot type `/` or `?` in the integrated terminal with a non-US keyboard layout (French AZERTY, macOS)

## Summary

On macOS with a French AZERTY layout, shifted punctuation characters cannot be typed in the VS Code **integrated terminal** inside tode. `/` (Shift+`:` on AZERTY) and `?` (Shift+`,`) produce nothing (or the unshifted character). Typing in the editor pane mostly works.

## Environment

- tode version: v0.1.13 (code-server 4.132.0)
- Host terminal: Ghostty
- macOS: Darwin 25.6.0
- Keyboard layout: French AZERTY (system input source)

## Steps to reproduce

1. Set the macOS input source to French (AZERTY).
2. Launch `tode` and open the integrated terminal.
3. Type `/` (Shift+`:`) or `?` (Shift+`,`).

**Expected:** the character is inserted in the terminal.
**Actual:** nothing is inserted (or the unshifted base character).

Switching the macOS input source to U.S. QWERTY makes both characters work again, which confirms the layout dependency.

## Analysis (from reading terminal-browser source)

The key event is translated at several layers and the *layout-resolved* character is lost along the way:

1. **Kitty keyboard protocol parsing** — `engine/crates/pixel-core/src/terminal.rs`, `parse_kitty_key()`: the engine keeps the protocol's *unshifted* unicode key code (`:` / `,` on AZERTY) as `Key::Char`. The progressive-enhancement flags requested are `\x1b[>27u` (1+2+8+16), i.e. **flag 4 "report alternate keys" is not requested**, so the shifted key code (`/`, `?`) is ...