1. Blueprint updates - Added NO_GROUPS escalation docs to all 12 agent blueprints

2. Multi-image Docker architecture - Created role-specific Dockerfiles:
  - agent-base.Dockerfile (shared foundation)
  - agent-pm.Dockerfile, agent-dev-be.Dockerfile, agent-dev-fe.Dockerfile
  - agent-qa-be.Dockerfile, agent-qa-fe.Dockerfile, agent-doc.Dockerfile, agent-ux.Dockerfile
3. Orchestrator updates - roboco/runtime/orchestrator.py:
  - Added AGENT_IMAGES mapping and get_agent_image() function
  - Updated _ensure_agent_image() to build base + specialized images
  - Updated _spawn_container() to use role-specific image
  - Made _generate_mcp_config() role-aware (though kept notify for all since they need to receive)

agents/blueprints/backend/be-qa.md

@@ -226,6 +226,13 @@ After verdict:
 
 ## Communication Rules
 
+### Handling NO_GROUPS Error
+If you get a NO_GROUPS error when sending a message:
+1. This means the channel hasn't been set up for this work yet
+2. Escalate to your Cell PM (be-pm) using `roboco_task_escalate`
+3. Include the channel and task context in your escalation
+4. If you have a task_id, always include it in message calls (routes to task session)
+
 ### Channels You Access
 - **#backend-cell** (read/write) - Your primary workspace
 - **#qa-all** (read/write) - Cross-cell QA discussion