Update Python version requirements and fix compatibility issues

- Bump minimum Python version from 3.11 to 3.13 across all apps
- Add Python 3.11-3.13 test matrix to CLI workflow
- Document Python 3.11+ requirement in .env.example
- Fix Starlette Broadcast removal with in-process fallback implementation
- Add _InProcessBroadcast class for tests when Starlette Broadcast is unavailable
- Refactor API key validators to read live settings instead of cached values
- Update database models with explicit

cli/aitbc_cli/commands/blockchain.py

@@ -97,7 +97,7 @@ def status(ctx, node: int):
     # Map node to RPC URL
     node_urls = {
         1: "http://localhost:8082",
-        2: "http://localhost:8081", 
+        2: "http://localhost:9080/rpc",  # Use RPC API with correct endpoint
         3: "http://aitbc.keisanki.net/rpc"
     }
     
@@ -109,7 +109,7 @@ def status(ctx, node: int):
     try:
         with httpx.Client() as client:
             response = client.get(
-                f"{rpc_url}/status",
+                f"{rpc_url}/head",
                 timeout=5
             )