Adds note on how to expose host browsers on NixOS for the flatpak install.

Flake lock file updates:

• Updated input 'git-hooks-nix':
'github:cachix/git-hooks.nix/f092770' (2026-01-01)
→ 'github:cachix/git-hooks.nix/a1ef738' (2026-01-22)
• Updated input 'nixpkgs':
'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.2511.905755%2Brev-2c3e5ec5df46d3aeee2a1da0bfedd74e21f4bf3a/019bbd9a-e3d9-7ccf-8dc2-3b9a70d0cdf8/source.tar.gz' (2026-01-13)
→ 'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.2511.906709%2Brev-fa83fd837f3098e3e678e6cf017b2b36102c7211/019c084c-b4eb-7e65-90ad-f4fc053d9dee/source.tar.gz' (2026-01-28)
• Updated input 'treefmt-nix':
'github:numtide/treefmt-nix/e96d59d' (2026-01-11)
→ 'github:numtide/treefmt-nix/28b19c5' (2026-01-29)

* config: add stay_alive

* main: respect cfg.StayAlive

* window_Settings: update StayAlive

* settings: add stay alive option

* abstract launcher config and add ui helpers

* don't allow resizing of launcher

* calculate button size from icon size

Added Ko-fi username for funding support.

* add rewrite rules

* fixup messaging/language

* add support for regex redirections

* fixup language

* add more redirection tests

* add separators to settings window

* rm unused conditiosn edit gialog

* set redirection dialog to fit element size

* clean up dialog helpers

* fmt

* abstract scrolled windows with createScrolledWindow()

* README.md: cleanup features

* data/metainfo: add new description to include redirect rules

* add support for negate condition property

* add GUI for negative conditions

* update docs

* docs: add URI scheme

* fixup fmt

* use net/url for better url parsing, handle special schemas, improve tests

* main: handle xdg-open for rejected URLs

* url: switch to allowlist for URI schemes

* fixup tests

* data: provide switchyard:// scheme

* add handleSwitchyardURL

* add tests for switchyard:// urls

* data/metainfo: improve summary

* README.md: document URI scheme