fix: set quick capture window title

[dannrs]

Summary

This small PR fixes the title of the quick capture window, making it distinguishable from the main ZenNotes window on Wayland compositors.

The quick capture window now has a different title: ZenNotes Quick Capture

This gives compositor rules something stable to match against.

Fixes #155

Testing:

• Open ZenNotes on Linux with a Wayland compositor. I tested with niri.
• Open the quick capture window.
• Run niri msg pick-window or an equivalent window inspection command.
• Confirm that the title of the quick capture window is now: ZenNotes Quick Capture.

[adibhanna]

Merged into the active release branch (`release/v2.4.0`) as b26395b rather than via this PR — your branch also carried two unrelated commits from `main` (the GitHub Sponsors / `FUNDING.yml` changes), so I cherry-picked just your fix commit onto the release branch to keep it clean. Your authorship is preserved on the commit. Nothing was rejected — this ships in v2.4.0.

Thanks @dannrs! Clean, correct fix: the constructor `title` plus `document.title` in `QuickCaptureApp` is exactly the right combo so the title sticks after the renderer loads, giving Wayland compositors (niri & co.) a stable `ZenNotes Quick Capture` toplevel to match against. Closes #155.