Happy crashes when switching input devices to local mode #443

Description

Happy crashes completely when switching input from a remote device (e.g., iPhone via Universal Control) back to the main computer and entering local mode.

Environment

• Happy version: 0.11.2
• Claude Code version: 2.0.14
• OS: macOS (Darwin 24.6.0)
• Device setup: MacBook Pro M4 with iPhone input via Universal Control/Continuity

Steps to Reproduce

1. Start Happy on Mac
2. Begin typing from iPhone (via Universal Control or similar remote input method)
3. Press space twice to trigger local mode switch
4. Happy crashes completely and exits

Expected Behavior

Happy should gracefully handle the local mode switch even when input device state changes mid-session.

Actual Behavior

Happy crashes immediately with no error message when attempting to switch to local mode after device input switch.

Root Cause

When the input device switches mid-session, the TTY state becomes inconsistent. The code calls `process.stdin.setRawMode()` without error handling, which throws an exception when stdin is in an inconsistent state due to the device switch.

Affected Code Locations

• `dist/index-sSOy3f2x.mjs:2503` (setRawMode true)
• `dist/index-sSOy3f2x.mjs:2798` (setRawMode false)
• `dist/index-DmJ8WyYo.cjs:2525` (setRawMode true)
• `dist/index-DmJ8WyYo.cjs:2820` (setRawMode false)
• `dist/runCodex-BnjA1TX6.mjs:951` (setRawMode true)
• `dist/runCodex-DQPZNHzH.cjs:953` (setRawMode true)

Note: The runCodex files already have try-catch when setting to false (lines 1310-1313 and 1312-1314 respectively), but not when setting to true. The main index files have no error handling at all.

Proposed Fix

Wrap all `setRawMode()` calls in try-catch blocks to gracefully handle TTY state inconsistencies:

```javascript
if (process.stdin.isTTY) {
try {
process.stdin.setRawMode(true); // or false
} catch (err) {
logger.debug(`Failed to set raw mode: ${err.message}`);
}
}
```

This fix allows Happy to continue operating even when TTY state is inconsistent due to input device switching.

Workaround

Until fixed, avoid pressing space twice when typing from a remote device, as this triggers the local mode switch that causes the crash.

Status

I have tested a local patch with this fix and can confirm it resolves the crash. Happy now switches to local mode gracefully even when input device state changes.