refactor: rename 'topics/summaries' to 'insights' throughout codebase
Complete vocabulary elevation to establish three-layer architecture:
Captures → Extracts → Insights
Key changes:
- Rename think/topics/ → think/insights/ (template directory)
- Rename think/summarize.py → think/insight.py
- Rename get_topics() → get_insights() in think/utils.py
- Rename scan_summaries/search_summaries → scan_insights/search_insights
- Update CLI command: think-summarize → think-insight
- Update API endpoints: /api/topics → /api/insights
- Update MCP tool: search_summaries → search_insights
- Update stats keys: topics_processed → insights_processed
- Update all path references from "topics/" to "insights/"
- Update documentation (JOURNAL.md, CRUMBS.md, AGENTS.md)
- Update fixtures and tests to use new naming
- Rename indexer database: summaries.sqlite → insights.sqlite
Note: Real journal data at $JOURNAL_PATH needs manual migration of
YYYYMMDD/topics/ directories to insights/ and JSON source field updates.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>