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

resources/gresource.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <gresources>
-  <gresource prefix="/minesweeper">
+  <gresource prefix="/io/github/bemagri/nomines">
     <file alias="bomb-solid">bomb-solid.svg</file>
     <file alias="explosion-solid">explosion-solid.svg</file>
     <file alias="flag-regular">flag-regular.svg</file>