Integrate ACMS execute-phase context assembly into LLMExecuteActor and inject assembled context into execute prompts with resilient fallback when assembly fails or returns empty output.
Wire the plan CLI executor to use an ACMS-backed execute context assembler, add Behave coverage for context injection/fallback/empty context, and extend Robot M5 verification helpers to assert execute-phase ACMS context usage.
ISSUES CLOSED: #850