Sends input data to an active PTY session.

Use this tool to:
- Type commands or text into an interactive terminal
- Send special key sequences (Ctrl+C, Enter, arrow keys, etc.)
- Respond to prompts in interactive programs

Usage:
- `id`: The PTY session ID (from pty_spawn or pty_list)
- `data`: The input to send (text, commands, or escape sequences)

Common escape sequences:
- Enter/newline: "\n" or "\r"
- Ctrl+C (interrupt): "\x03"
- Ctrl+D (EOF): "\x04"
- Ctrl+Z (suspend): "\x1a"
- Tab: "\t"
- Arrow Up: "\x1b[A"
- Arrow Down: "\x1b[B"
- Arrow Right: "\x1b[C"
- Arrow Left: "\x1b[D"

Returns success or error message.

Examples:
- Send a command: data="ls -la\n"
- Interrupt a process: data="\x03"
- Answer a prompt: data="yes\n"
