/insights: consider stronger model or dedup against existing CLAUDE.md

Preflight

• [x] I've searched existing issues and this isn't a duplicate
• [x] This is a single feature request (not multiple)

Problem Statement

The /insights command generates recommendations that duplicate rules and conventions already present in the user's CLAUDE.md files. For users who maintain thorough project configurations, this reduces the signal-to-noise ratio of the report significantly.

The underlying issue appears to be that the model used for analysis doesn't have visibility into the user's existing CLAUDE.md content, so it can't filter out suggestions that are already codified.

Proposed Solution

Any of these would improve the experience:

1. Deduplication pass — Before finalizing the report, cross-reference recommendations against the user's CLAUDE.md files and filter out anything already covered
2. Model flag — Allow a --model override for users willing to trade cost for higher-quality reasoning
3. Smarter context — Feed existing CLAUDE.md content into the analysis prompt so the model can focus on genuinely novel insights

The ideal outcome is that recommendations only surface actionable items not already present in the user's project configuration.

Alternative Solutions

Currently the only workaround is manually reviewing the report and mentally filtering out suggestions that are already implemented — which defeats the purpose of an automated insights tool.

Priority

Medium - very helpful improvement

Feature Category

CLI commands

Use Case Example

1. User has a well-maintained CLAUDE.md with documented conventions (e.g., commit format, testing strategy, code style rules)
2. User runs /insights
3. Report recommends adding conventions that are already documented in CLAUDE.md
4. User has to manually sift through duplicates to find genuinely new suggestions

With the proposed change, step 3 would only surface recommendations not already covered by existing configuration.

Additional Context

This would make /insights substantially more useful for power users who have already invested in configuring their projects. The current experience can feel like the tool isn't aware of the work you've already done.