Review of #112: syncSelectedInputSource() treated an empty device name as
"nameless device — invalidate rather than guess" and called removeItem()
on the persisted selection. But the input dropdown's first option is
literally `<option value="">Default</option>`, so "" is the ordinary
"use the OS default" choice, not a nameless device.
init()'s auto-apply calls this on every startup, so a user sitting on
Default had their capability selection deleted at each launch — and that
selection is made in a DIFFERENT ui (the input_setup / tuner picker), so
this silently discarded a device they explicitly chose. Because
audioInputOpenHandler deliberately refuses to guess a device, a cleared
selection leaves plugins with no input at all: the same dead-guitar
symptom the PR set out to fix. Confirmed against the pre-fix build — a
sync with the Default value emits removeItem on the stored key.
"" now means "no opinion": leave the selection to the picker that owns it.
Also extract inputSourceNameKey() as the single place a named input's key
is built. Registration and selection were formatting the same template
independently and had already drifted on the nameless branch (registration
falls back to a positional key; sync emitted none). Tests pin the format,
the Default behaviour, and a round-trip through the open handler's own
parser regex.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
