refactor: move project under backend

backend/infra/docker/keagate/local.json

@@ -0,0 +1,21 @@
+{
+  "HOST": "https://capay.hao.work/backend",
+  "PORT": 8081,
+  "MONGO_CONNECTION_STRING": "mongodb://localhost:27017",
+  "MONGO_KEAGATE_DB": "keagate",
+
+  "IP_WHITELIST": ["127.0.0.1"],
+  "TRANSACTION_TIMEOUT": 1200000,
+  "TRANSACTION_MIN_REFRESH_TIME": 30000,
+  "TRANSACTION_SLIPPAGE_TOLERANCE": 0.02,
+
+  "SEED": "hex-128-bit-seed",
+  "KEAGATE_API_KEY": "replace-api-key",
+  "INVOICE_ENC_KEY": "hex-32-bytes",
+  "IPN_HMAC_SECRET": "replace-hmac-secret",
+
+  "SOL": {
+    "ADMIN_PUBLIC_KEY": "SolPublicAddress",
+    "ADMIN_PRIVATE_KEY": null
+  }
+}