Add floating recording indicator actions

[phoenixray2000]

Summary

• add an always-on-top floating recording timer with a Settings toggle
• share the tray context menu with the floating timer and add Open Recordings Folder
• keep the finished state visible for 5 seconds and let a second click open the recordings folder

Stack

• Depends on upstream PR Add output formats and quality controls #4: Add output formats and quality controls
• Depends on upstream PR Improve audio normalization for voice clarity #5: Improve audio normalization for voice clarity
• This PR uses fork branch phoenixray2000:codex-floating-recording-indicator-upstream because this account cannot push stack base branches to lukmay/QuickAudioRecorder.

Validation

• python -m unittest discover -s tests
• git diff --check codex-normalize-audio-upstream..codex-floating-recording-indicator-upstream