refactor: rename service to autostart, fix fork bomb, add rfd file picker, use dirs crate, auto-start launcher, propagate overlays, ensure icon

- Rename service module to autostart (no systemd service is used)
- Fix fork bomb: replace subprocess spawning with thread::spawn
- Replace zenity/kdialog with rfd crate for XDG Portal file picker
- Use dirs crate instead of env::var("HOME")
- Auto-start launcher before game launch for online auth
- Propagate gamemode/mangohud env vars to launcher process
- Auto-install SVG icon on startup via ensure_icon()
- Add assets/umutray.svg
- Remove stale zenity/kdialog optdepends from PKGBUILD
- Update .gitignore for .claude/ and CLAUDE.md

Cargo.toml

@@ -46,3 +46,9 @@ reqwest = { version = "0.12", features = ["blocking", "json"] }
 iced = { version = "0.13", features = ["tokio"] }
 iced_fonts = { version = "0.1", features = ["bootstrap"] }
 tokio = { version = "1.52.1", features = ["rt"] }
+
+# PE exe version info (game name detection)
+pelite = "0.10"
+
+# Native file dialogs via XDG Desktop Portal
+rfd = "0.15"