hermes - 💡(How to fix) Fix [Feature]: Allow null-result outcomes in bg-review's skill update prompt

Problem or Use Case

The bg-review prompt at agent/background_review.py:48-51 (the _SKILL_REVIEW_PROMPT constant) instructs the review agent:

"Review the conversation above and update the skill library. Be ACTIVE — most sessions produce at least one skill update, even if small. A pass that does nothing is a missed learning opportunity, not a neutral outcome."

This frames inaction as failure. Predictable consequence: the review model produces edits even when no clear signal warrants one. Concrete case: a daily-briefing cron run with no user correction, no novel pattern, no skill consulted — bg-review still authored two complementary-but-overlapping reference files in 9 seconds. The vague target ("at least one skill update, even if small") combined with the "missed opportunity" framing manufactures noise.

For comparison, the parallel _MEMORY_REVIEW_PROMPT already allows honest null results: "If nothing is worth saving, just say 'Nothing to save.' and stop." The skill review prompt does not have an equivalent escape hatch.

Proposed Solution

Reframe the skill review prompt to allow honest null outcomes, e.g.:

"Review the conversation above and update the skill library only when a clear signal warrants it (user corrections, frustration markers, novel patterns, outdated content, missing pitfalls). Prefer patching an existing skill over creating a new file. If no signal fired this session, respond exactly 'No update warranted.' — null results are valid."

Keep the existing "preference order" (update loaded skill → update umbrella → add support file) as guidance for when to act, just not as pressure to always act.

Alternatives Considered

• Leave the prompt and raise creation_nudge_interval default — fires less often, but each firing still has the action bias.
• Make the prompt configurable via skills.bg_review_prompt_override — gives users an escape hatch but does not fix the bundled default.

Feature Type: Configuration option Scope: Small