chore: cleanup for push to main

- Remove CLAUDE.md, TODO.md (dev-only task trackers)
- Remove umutray.service (unused systemd unit)
- Remove .vscode/settings.json (stale Makefile ref)
- Add src/theme.rs (shared palette/styling module)
- Update .gitignore: exclude .vscode/, packaging build artifacts
- Fix README: add gui command, correct service description
- Delete ~1.3GB packaging build artifacts from working tree

Code changes from prior session (already committed locally):
- Tray icon launches alongside GUI, close dialog with minimize-to-tray
- Theme module extraction, button shadow fixes, UI polish
- Game detection filtering, prettify_game_name, Battle.net fix

packaging/PKGBUILD

@@ -48,13 +48,11 @@ build() {
 package() {
     cd "$pkgname"
 
-    # Binary — install to ~/.local/bin for user-local usage
-    install -Dm755 target/release/umutray "${HOME}/.local/bin/umutray"
+    # Binary
+    install -Dm755 target/release/umutray "$pkgdir/usr/bin/umutray"
 
-    # App menu entry for the current user
-    install -Dm644 umutray.desktop "${HOME}/.local/share/applications/umutray.desktop"
-    sed -i "s|Exec=umutray|Exec=${HOME}/.local/bin/umutray|" \
-        "${HOME}/.local/share/applications/umutray.desktop"
+    # App menu entry
+    install -Dm644 umutray.desktop "$pkgdir/usr/share/applications/umutray.desktop"
 
     # License
     install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"