Meta: Restore / Add Minimize-to-Tray or Close-to-Tray Support (with Visualizer Enhancements)

Several users have reported or requested the ability for the application to minimize/close to the system tray instead of fully exiting or staying in the taskbar.
Additionally, users have asked for better tray visualization when Whispering is actively recording (e.g., changing tray icon, small popup/visualizer).

This issue will serve as the master tracker for all related requests and bug reports. Other issues will be closed as duplicates and linked here.

Problem

• Prior to v7.0.1, the app supported minimizing/closing to tray.
• The feature was removed due to bugs with closing behavior (Whispering v7.0.0 - Linux AppImage cannot be closed once open (must kill it) #550, Whispering v7 Window Won’t Close – Any Solution? #556).
• Since then, many users have requested its return, as it's a common expected behavior for background/utility apps.
• Current behavior forces the app to remain open in the taskbar, which users find intrusive.
• Users also want clear feedback when the app is recording while hidden in the tray.

Motivation

• Cleaner Taskbar: Keep taskbar uncluttered by background apps.
• Background Operation: Useful for global shortcuts, recording, or running silently.
• Better UX for Recording: Visual indicator (tray icon state change or popup visualizer) to reassure users that Whispering is active.

Related Issues

• Minimise to tray #824 — Request for minimize/close-to-tray option
• Whispering: Lost "close to tray" option #714 — Regression: feature existed in older versions, now missing
• Feature: Option to dock to the menu bar instead of always being open #656 — Option to dock to menu bar instead of being always open
• Better visualization for when Whispering is Recording #624 — Better visualization when Whispering is recording
• Add a setting to "Minimize to Systray" #607 — Feature request: minimize to tray instead of taskbar
• 7.0.1 Option to close in tray, is it not available more? #563 — Close-in-tray removed in 7.0.1

Todos

• Investigate: Why the original close-to-tray implementation was buggy (Whispering v7.0.0 - Linux AppImage cannot be closed once open (must kill it) #550, Whispering v7 Window Won’t Close – Any Solution? #556).
• Settings: Add user preferences for
  • Close action → Exit app / Minimize to tray
• Implement: Restore tray integration using Tauri system tray APIs
• Tray Visualization (from Better visualization for when Whispering is Recording #624):
  • Change tray icon state when recording is active
  • Optional: small popup/audio visualizer when recording starts
  • Consider tooltip updates (e.g., "Recording…" vs "Idle")
• Testing:
  • Windows
  • macOS
  • Linux
• Documentation: Update user guide and changelog with new tray options.

✅ This issue will remain open as the primary tracker until the feature is re-implemented with tray visualization.