Release 1.0.0: rename to NoMines, add leaderboard, theme support and release metadata

- Rename app/binary/app-id to nomines (io.github.bemagri.nomines), config dir
  moves to ~/.config/nomines with legacy path fallback
- Add persistent best-time leaderboard (Glib::KeyFile)
- Theme-aware board following system light/dark preference
- Beveled 3D cells, confetti win animation, keyboard shortcuts,
  right-click chording, per-difficulty window sizing
- Add AppStream metainfo, validate desktop file and metainfo via meson tests
- Fix license metadata to GPL-3.0-or-later and real homepage

.gitignore

@@ -1,5 +1,6 @@
 # Build directories
 build/
+build-*/
 _build/
 bin/
 lib/
@@ -37,6 +38,7 @@ obj/
 *.exe
 *.out
 *.app
+nomines
 minesweeper
 
 # CMake and build system
@@ -141,8 +143,12 @@ $RECYCLE.BIN/
 *.gresource
 
 # Leaderboard and config files
+.config/nomines/
 .config/minesweeper/
 
 #MacOS files
 .cache/
 .DS_Store
+
+# direnv
+.direnv/