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>

pkg/ferrous-solitaire-server/ferrous-solitaire-server.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=Ferrous Solitaire Sync Server
+Documentation=https://github.com/funman300/ferrous-solitaire/blob/main/README_SERVER.md
+After=network.target
+
+[Service]
+Type=simple
+User=ferrous-solitaire
+Group=ferrous-solitaire
+EnvironmentFile=/etc/ferrous-solitaire-server/server.env
+ExecStart=/usr/bin/solitaire_server
+Restart=on-failure
+RestartSec=5s
+
+# Harden the service
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/var/lib/ferrous-solitaire-server
+
+[Install]
+WantedBy=multi-user.target