Remove floating widget — move controls to toolbar icon #4028

Originally written by @ccantynz-alt on GitHub.
Imported from https://github.com/ccantynz-alt/48co.v1/pull/9

The on-page widget was blocking page UI (covering Claude's reply button, etc). This completely removes it.

What changed:

• content.js: Removed entire Shadow DOM widget (panel, mic button, waveform, drag zone — all gone). Replaced with a tiny toast notification that appears briefly at top-center for status changes (Recording... / Transcribing... / Typed), then fades away.
• background.js: Added badge updates on the extension toolbar icon (REC in red while recording, checkmark in green when done). Added TOGGLE_RECORDING message type for popup button.
• popup.html: Added a big mic toggle button at the top of the popup so clicking the extension icon gives instant access. Updated shortcuts section (removed scroll references, added middle-click).
• popup.js: Mic toggle sends TOGGLE_RECORDING and closes popup.

How to trigger recording (no widget needed):

1. Middle-click anywhere on the page
2. Ctrl+Shift+Space keyboard shortcut
3. Click extension icon → click mic button
4. Hold Ctrl+Shift (push-to-talk mode)

https://claude.ai/code/session_01PBeNmPHrD2W6A2YKZRC7V3