autopilot: noop step + summarizer

[Angelmmiguel]

Summary

Add the noop step that records "no action needed" decisions, plus the trace summarizer used for lightweight summaries.

Requirements

Noop Step (lib/autopilot/steps/noop.ts)

• Receives noop actions from the coordinator when no action is needed
• Uses haiku model (lightweight) for trace summarization
• Records "no action" outcome to memory
• maxParallel: 5
• Terminal step (no further actions produced)
• Prompt: steps/prompts/summary-prompt.md (~2KB)

Summarizer (lib/autopilot/summarizer.ts)

• Trace summarization logic used by noop and other steps
• Generates concise summaries of trace execution history

Tests

• Noop recording with summary
• Summarizer output quality
• Memory write on noop

References

• Reference noop: rover-autopilot/packages/cli/src/lib/autopilot/steps/noop.ts
• Reference summarizer: rover-autopilot/packages/cli/src/lib/autopilot/summarizer.ts
• Prompt: rover-autopilot/packages/cli/src/lib/autopilot/steps/prompts/summary-prompt.md