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/time_attack_plugin.rs

@@ -307,7 +307,7 @@ mod tests {
             .add_plugins(TimeAttackPlugin);
         app.init_resource::<ButtonInput<KeyCode>>();
         // Disable session persistence — tests must not touch the real
-        // ~/.local/share/solitaire_quest/time_attack_session.json.
+        // ~/.local/share/ferrous_solitaire/time_attack_session.json.
         app.insert_resource(TimeAttackSessionPath(None));
         // The plugin's startup-load hook may have populated TimeAttackResource
         // from a real on-disk session. Reset it so each test starts inactive.