chore: rename app from Solitaire Quest to Ferrous Solitaire

Updates all in-tree references:
- Android package: com.solitairequest.app → com.ferrousapp.solitaire
- APK name: solitaire-quest → ferrous-solitaire
- Data dir: solitaire_quest → ferrous_solitaire (across all 6 data modules + engine)
- Keyring service: solitaire_quest_server → ferrous_solitaire_server
- Android Keystore key: solitaire_quest_token_key → ferrous_solitaire_token_key
- Gitea repo: Rusty_Solitare → Ferrous-Solitaire (also fixes "Solitare" typo)
- Renamed pkg/solitaire-quest* → pkg/ferrous-solitaire*
- Updated ArgoCD, docker-compose, CI workflow, build script, all docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_engine/src/game_plugin.rs

@@ -1302,7 +1302,7 @@ mod tests {
 
     /// Build a minimal headless `App` with just `GamePlugin` installed.
     /// Disables persistence and overrides the seed so tests are deterministic
-    /// and don't touch `~/.local/share/solitaire_quest/game_state.json`.
+    /// and don't touch `~/.local/share/ferrous_solitaire/game_state.json`.
     fn test_app(seed: u64) -> App {
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(GamePlugin);
@@ -1316,7 +1316,7 @@ mod tests {
         // can't leak into per-test world state and trip the
         // `pending.0.is_some()` guard in `auto_save_game_state` /
         // `save_game_state_on_exit`. Without this clear, an
-        // unrelated `~/.local/share/solitaire_quest/game_state.json`
+        // unrelated `~/.local/share/ferrous_solitaire/game_state.json`
         // would silently disable the auto-save path under test.
         app.insert_resource(PendingRestoredGame(None));
         // Override the system-time seed with a known value.