chore: initialize repository with deployment baseline

entities/BillingPlan.json

@@ -0,0 +1,83 @@
+{
+  "name": "Invoice",
+  "type": "object",
+  "properties": {
+    "invoice_number": {
+      "type": "string",
+      "title": "Invoice Number"
+    },
+    "tenant_id": {
+      "type": "string",
+      "title": "Tenant ID"
+    },
+    "tenant_name": {
+      "type": "string",
+      "title": "Tenant Name"
+    },
+    "status": {
+      "type": "string",
+      "enum": [
+        "draft",
+        "pending",
+        "paid",
+        "overdue",
+        "cancelled",
+        "refunded"
+      ],
+      "title": "Status"
+    },
+    "amount": {
+      "type": "number",
+      "title": "Amount"
+    },
+    "currency": {
+      "type": "string",
+      "enum": [
+        "NGN",
+        "USD",
+        "GHS",
+        "KES",
+        "ZAR"
+      ],
+      "title": "Currency"
+    },
+    "due_date": {
+      "type": "string",
+      "format": "date",
+      "title": "Due Date"
+    },
+    "paid_date": {
+      "type": "string",
+      "format": "date",
+      "title": "Paid Date"
+    },
+    "payment_provider": {
+      "type": "string",
+      "enum": [
+        "paystack",
+        "flutterwave",
+        "manual"
+      ],
+      "title": "Payment Provider"
+    },
+    "payment_reference": {
+      "type": "string",
+      "title": "Payment Reference"
+    },
+    "line_items": {
+      "type": "string",
+      "title": "Line Items JSON"
+    },
+    "notes": {
+      "type": "string",
+      "title": "Notes"
+    }
+  },
+  "required": [
+    "invoice_number",
+    "tenant_id",
+    "status",
+    "amount",
+    "currency"
+  ]
+}