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

AGENTS.md

@@ -0,0 +1,41 @@
+# AGENTS.md
+
+GTK4/gtkmm4 Minesweeper clone ("NoMines") in C++20, built with Meson. ~800 lines total.
+
+## Build & run
+
+```bash
+meson setup build        # or reuse existing build/
+meson compile -C build
+./build/nomines
+```
+
+- Dev deps come from the Nix flake via direnv (`.envrc` uses `use flake`); `nix develop` works standalone.
+- Alternative: `nix build` / `nix run`.
+- No unit tests; two optional release-validation tests (desktop file + AppStream metainfo via `desktop-file-validate`/`appstreamcli`) are auto-added when those tools exist.
+- `build/compile_commands.json` exists for clangd (it's gitignored, regenerate with `meson setup --wipe build` if stale).
+- WARNING: flake builds only see git-tracked files. New source files must be `git add`ed before `nix build` works.
+
+## Architecture
+
+- `src/minefield.*` — pure game logic, no GTK: `Minefield` (board state, flag counting, chording), `Cell` bitfield, `GameDifficulty` presets, `GameState` enum.
+- `src/board_widget.*` — `Gtk::DrawingArea`; all rendering is hand-drawn Cairo primitives (draw_cell/draw_digit/draw_flag/draw_bomb), input via `Gtk::GestureClick` + `EventControllerMotion`, confetti particle animation on win (frame-rate independent via `Gdk::FrameClock`).
+- `src/window.*` — `Gtk::ApplicationWindow` with HeaderBar, difficulty popover (radio-style `CheckButton`s), leaderboard popover, timer; owns the `shared_ptr<Minefield>` and swaps it on new game. Keyboard shortcuts via `Gtk::EventControllerKey` (R/Ctrl+N new game, 1-4 difficulties, L leaderboard).
+- `src/leaderboard.*` — persistent best times per difficulty via `Glib::KeyFile` at `~/.config/nomines/leaderboard.ini` (recorded on win, shown in a header-bar popover; falls back to the pre-1.0 `~/.config/minesweeper/` path for migration). NOTE: uses the glibmm 2.80 refcounted `KeyFile::create()` API and gtkmm 4.14 `CheckButton` (a `Widget`+`Actionable`, not a `Button` — use `signal_toggled()` + `get_active()`, and `set_group(CheckButton&)`).
+- glibmm 2.80 quirk: `SignalProxy<R(T...)>::connect()` (non-void return signals like `signal_key_pressed`) requires the `after` bool explicitly — `connect(slot, false)`. Void signals default it to true.
+- `src/main.cpp` — single `Gtk::Application` (`io.github.bemagri.nomines`); `make_window_and_run<MainWindow>`.
+
+## Release
+
+- Version `1.0.0` is stamped in FOUR places: `meson.build`, `flake.nix`, `default.nix`, and the `<releases>` entry in `resources/io.github.bemagri.nomines.metainfo.xml`. Bump all four together.
+- Release sanity: `nix build .` (validates the flake), `desktop-file-validate` + `appstreamcli validate --no-net` on the resources (wired up as meson tests).
+- The metainfo screenshot URL points at `raw.githubusercontent.com/bemagri/nomines/main/...` — it 404s until the repo is published; replace if the repo moves.
+
+## Gotchas
+
+- `resources/gresource.xml` + the `gnome.compile_resources` step in `meson.build` compile unused code: the app never loads these SVGs/textures (the `confetti.png` is also unused). All art is Cairo-drawn. Don't extend the GResource to implement visual features; draw with Cairo instead.
+- README's feature list is mostly accurate but not trustworthy in detail; verify against code. (An older `leaderboard.txt` CSV may linger in `~/.config/minesweeper/` from a previous experiment — the app now uses `~/.config/nomines/leaderboard.ini`.)
+- Code style: snake_case methods/fields, trailing `_` on private members, `#pragma once`, nested-struct headers. C++20 stdlib only, no third-party libs beyond gtkmm/sigc++.
+- Board colors are theme-aware: `BoardWidget::resolve_palette()` maps GTK CSS named colors (`theme_bg_color`, `theme_base_color`, ...) to a light/dark palette each draw. Don't hardcode light grays in `draw_*` helpers; thread the `Palette` through instead.
+- Meson source list is explicit in `meson.build` — new source files must be added there.
+- `.direnv/` and `build*/` are gitignored; flake builds require files to be committed/tracked.