refactor: restructure test suite

- Remove tests/production/ directory (JWT auth, production monitoring, etc.)
- Remove tests/staking/ directory
- Remove tests/services/test_staking_service.py
- Remove tests/phase1/ directory
- Remove tests/load_test.py
- Add tests/verification/ directory with 20+ new test files
- Add tests/load/locustfile.py for load testing
- Add tests/security/test_confidential_transactions.py
- Add tests/integration/test_working_integration.py
- Update docs/ for minimum Python version and paths

tests/verification/register_test_clients.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+"""Register test clients for payment integration testing"""
+
+import asyncio
+import httpx
+import json
+
+# Configuration
+COORDINATOR_URL = "http://127.0.0.1:8000/v1"
+CLIENT_KEY = "test_client_key_123"
+MINER_KEY = "${MINER_API_KEY}"
+
+async def register_client():
+    """Register a test client"""
+    async with httpx.AsyncClient() as client:
+        # Register client
+        response = await client.post(
+            f"{COORDINATOR_URL}/clients/register",
+            headers={"X-API-Key": CLIENT_KEY},
+            json={"name": "Test Client", "description": "Client for payment testing"}
+        )
+        print(f"Client registration: {response.status_code}")
+        if response.status_code not in [200, 201]:
+            print(f"Response: {response.text}")
+        else:
+            print("✓ Test client registered successfully")
+
+async def register_miner():
+    """Register a test miner"""
+    async with httpx.AsyncClient() as client:
+        # Register miner
+        response = await client.post(
+            f"{COORDINATOR_URL}/miners/register",
+            headers={"X-API-Key": MINER_KEY},
+            json={
+                "name": "Test Miner",
+                "description": "Miner for payment testing",
+                "capacity": 100,
+                "price_per_hour": 0.1,
+                "hardware": {"gpu": "RTX 4090", "memory": "24GB"}
+            }
+        )
+        print(f"Miner registration: {response.status_code}")
+        if response.status_code not in [200, 201]:
+            print(f"Response: {response.text}")
+        else:
+            print("✓ Test miner registered successfully")
+
+async def main():
+    print("=== Registering Test Clients ===")
+    await register_client()
+    await register_miner()
+    print("\n✅ Test clients registered successfully!")
+
+if __name__ == "__main__":
+    asyncio.run(main())