[Issue]: Aptune quits abruptly when switching from a Bluetooth mic to the built-in mic via Spotlight launcher

[yyovil]

Expected behavior

Changing Aptune's capture input from a Bluetooth microphone back to the system or built-in microphone via the installed Spotlight action should switch the input route cleanly and keep Aptune running.

Actual behavior

When the capture input is changed this way, Aptune quits abruptly instead of continuing with the new input source.

Steps to reproduce

1. Start Aptune while the active capture/input source is a Bluetooth microphone.
2. Install the Spotlight launcher with aptune install-plugin built-in-mic if needed.
3. Open Spotlight and run Aptune Built-in Mic to switch Aptune back to the Mac's built-in microphone.
4. Observe that Aptune exits abruptly.

Environment

macOS 26.3.1 (25D2128)
MacBook Air (Apple M4, Mac16,12)
Spotlight launcher installed with aptune install-plugin built-in-mic
Launcher used: Aptune Built-in Mic
Original capture source: Bluetooth microphone
Target capture source: Mac built-in/system microphone

Suggested prompt

Investigate why aptune use-built-in-mic --replace-running causes Aptune to terminate when switching from a Bluetooth microphone to the Mac's built-in microphone via the Spotlight launcher. Check the device rerouting and replace-running path, and review ~/Library/Logs/Aptune/spotlight-launcher.log to identify why Aptune exits instead of staying running after the input source changes.