feat: add Sub2API application for AI API gateway platform

- Add Sub2API 1Panel application configuration
- Support subscription quota distribution, API Key management, billing and load balancing
- Include docker-compose.yml, data.yml, README documentation and logo
- Support amd64 and arm64 architectures

apps/sub2api/latest/data/config.yml

@@ -0,0 +1,26 @@
+server:
+  host: "0.0.0.0"
+  port: 8080
+  mode: "release"
+
+database:
+  host: "postgres"
+  port: 5432
+  user: "sub2api"
+  password: "${POSTGRES_PASSWORD}"
+  dbname: "sub2api"
+
+redis:
+  host: "redis"
+  port: 6379
+  password: ""
+
+jwt:
+  secret: "${JWT_SECRET}"
+  expire_hour: 24
+
+default:
+  user_concurrency: 5
+  user_balance: 0
+  api_key_prefix: "sk-"
+  rate_multiplier: 1.0