Add wired input lookup for Bluetooth default mics

[ComputelessComputer]

Opening a Bluetooth headset mic forces HFP: the headset gates the mic to silence between words (26-52% zeros measured on Shokz and Jabra) and drops the wearer to 16 kHz. Expose a helper that picks a wired input (built-in, then USB) when the default input is Bluetooth so the capture path can avoid the headset mic.

---

Note

Medium Risk
Changes default capture device selection and Windows device typing, which can alter which mic opens and AEC/isolation behavior; dropout detection is additive but affects live session UX.

Overview
When the system default input is a Bluetooth headset and the user did not pick a mic, capture on macOS/Windows now opens a wired input instead (built-in/PCI, then USB), skipping loopback/line-in endpoints, so opening the headset mic does not force HFP gating and narrowband audio. The source tracks active_mic_device separately from the user choice; progress/errors and GetMicDevice report what is actually open.

Windows transport classification now uses the adapter device path (e.g. bthhfenum) so in-box “Hands-Free” endpoints count as Bluetooth, not only names containing “bluetooth”.

After a swap, mic_isolated is no longer asserted even with headphone-only output (replacement is treated as a room mic). A DropoutMonitor watches raw mic for high exact-zero ratios and emits mic_dropouts once per stream (surfaced through listener and transcription events) when gating still happens.

^{Reviewed by Cursor Bugbot for commit fa366e8. Bugbot is set up for automated code reviews on this repo. Configure here.}

[netlify]

✅ Deploy Preview for anarlog canceled.

Name	Link
🔨 Latest commit	fa366e8
🔍 Latest deploy log	https://app.netlify.com/projects/anarlog/deploys/6a998712d3fe890008cd5077

[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 1a969af. Configure here.}