fix(simulation): interpret named special keys in ui.press

[kitlangton]

Problem

The canonical simulation action ui.press forwards its key string directly to OpenTUI mockInput.pressKey. Sending { "key": "escape" } types the literal word escape into the focused input instead of dispatching Escape.

This broke the OpenCode UI catalog after closing the command palette: the next slash command was entered into the still-open palette as escape/models.

Reproduction

1. Launch a simulated TUI through OpenCode Drive.
2. Open the command palette with ui.press for Ctrl+P.
3. Send ui.press with key: "escape".
4. Capture the terminal frame.

The palette remains open and its search contains escape.

Sending the raw escape byte "\u001b" works, but callers should not need transport-level key encoding for the protocol’s named key operation.

Expected

Named special keys such as escape are translated to the corresponding OpenTUI input event, with coverage for the canonical frontend simulation protocol.