feat: values-based autonomy framework and channel-agnostic triage

[cchen362]

Summary

• Add AUTONOMY_FRAMEWORK identity/values/systems prompt injected into all LLM calls
• Add platform-aware context builder for macOS/Windows/Linux
• Make heartbeat triage triggers channel-agnostic with _build_channel_guidance()
• Update default system prompt to values-aligned version

Context

Implementation Plan 002. Builds on PR #1 (cross-platform). Replaces hardcoded iMessage references in triage with dynamic channel guidance. Merge PR #1 first.

Test plan

• Verify AUTONOMY_FRAMEWORK appears in system prompt
• Verify platform context shows correct OS
• Verify triage triggers use channel_guidance placeholder

[ben4mn]

Thanks for this — interesting idea, but closing for now. A few concerns:

1. Personality changes without migration — this changes Edward's core system prompt and identity for existing users with no opt-in or migration path
2. Permanent token cost — ~380 extra tokens injected into every single LLM call adds up significantly
3. Self-evolution encouragement — "You can modify your own code" is a significant autonomy escalation that needs careful consideration
4. Forward references — references NotebookLM capabilities before PR feat: integrate Google NotebookLM as a skill with 12 tools #3 adds them, which would confuse the LLM
5. Channel-agnostic triage refactor is a good change but should be submitted separately

If you'd like to revisit the triage refactor as a standalone PR, that part would be welcome!