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

meson.build

@@ -1,5 +1,5 @@
-project('minesweeper', 'cpp',
-  version : '0.2.0',
+project('nomines', 'cpp',
+  version : '1.0.0',
   default_options : ['warning_level=3', 'cpp_std=c++20'])
 
 gnome = import('gnome')
@@ -25,24 +25,45 @@ src = [
     'src/minefield.cpp',
     'src/board_widget.hpp',
     'src/board_widget.cpp',
+    'src/leaderboard.hpp',
+    'src/leaderboard.cpp',
     res
 ]
 
 # Executable
-executable('minesweeper', 
+executable('nomines', 
     src, 
     dependencies : deps, 
     install : true
 )
 
-# Install icons
+# Install icon
 install_data(
-    'resources/minesweeper.svg',
+    'resources/nomines.svg',
     install_dir: join_paths(get_option('datadir'), 'icons/hicolor/scalable/apps')
 )
 
 # Install desktop file
 install_data(
-    'resources/org.gtkmm.minesweeper.desktop',
+    'resources/io.github.bemagri.nomines.desktop',
     install_dir: join_paths(get_option('datadir'), 'applications')
 )
+
+# Install AppStream metadata
+install_data(
+    'resources/io.github.bemagri.nomines.metainfo.xml',
+    install_dir: join_paths(get_option('datadir'), 'metainfo')
+)
+
+# Release validation (best-effort, only when the tools are installed)
+desktop_file_validate = find_program('desktop-file-validate', required: false)
+if desktop_file_validate.found()
+  test('validate-desktop', desktop_file_validate,
+       args: ['resources/io.github.bemagri.nomines.desktop'])
+endif
+
+appstreamcli = find_program('appstreamcli', required: false)
+if appstreamcli.found()
+  test('validate-metainfo', appstreamcli,
+       args: ['validate', '--no-net', 'resources/io.github.bemagri.nomines.metainfo.xml'])
+endif