fix: standardize all agent API endpoints to use /api/v1 prefix and update blockchain commands to use local node

- Change all agent endpoints from /agents/* and /v1/agents/* to /api/v1/agents/* for consistency
- Update client job submission endpoint from /v1/jobs to /api/v1/jobs
- Fix blockchain blocks command to query local node at /rpc/blocks-range instead of coordinator
- Fix blockchain peers command to query local node at /rpc/peers with RPC-only mode fallback
- Add proper error handling for blockchain

cli/aitbc_cli/commands/client.py

@@ -48,7 +48,7 @@ def submit(ctx, job_type: str, prompt: Optional[str], model: Optional[str],
         try:
             with httpx.Client() as client:
                 response = client.post(
-                    f"{config.coordinator_url}/v1/jobs",
+                    f"{config.coordinator_url}/api/v1/jobs",
                     headers={
                         "Content-Type": "application/json",
                         "X-Api-Key": config.api_key or ""