Global hotkey fallback to toggle mode causes stuck 'Transcribing...' state

[UriZafrir]

Problem

When the global hotkey fails to initialize on Linux (e.g., missing evdev permissions), the app silently falls back to toggle mode by setting push_to_talk = false (src/app/mod.rs:216).

Toggle mode is broken — handle_toggle() transitions the state enum (Idle → Recording → Transcribing) but never creates a CpalRecorder and never runs the transcription pipeline. This causes the app to get stuck on "Transcribing..." indefinitely.

Reproduce

1. Run on Linux without root/in input group (global hotkey fails to init)
2. Press space to start recording → shows "● REC 0.0s"
3. Press space to stop → stuck on "Transcribing..."

Root Cause

src/app/mod.rs:212-218 — when GlobalHotkey::new() fails:

Err(e) => {
    eprintln!("[voice] Warning: Could not set up global hotkey: {}", e);
    if self.config.push_to_talk {
        eprintln!("[voice] Falling back to toggle mode (press space to start/stop recording).");
        self.config.push_to_talk = false;  // <-- broken fallback
    }
}

Fix

Keep push_to_talk = true when the hotkey fails. The terminal keyboard (space) already works through the PTT path. Just warn the user the global hotkey is unavailable.