Add a topic taxonomy system to assign meaningful labels to flowchart
clusters on the browse page. Clusters get labels like "Fractions" or
"Linear Algebra" instead of just emoji groups.
Key changes:
- Database table `topic_taxonomy` to store labels and embeddings
- ~200 topic labels at multiple specificity tiers (broad, domain, specific)
- Client-side agglomerative clustering with MAX distance label assignment
- Admin panel at /flowchart/admin for managing seeds and taxonomy
- Test clustering tool to verify label assignments
The taxonomy is generated via LLM and stored in the database, with
fallback to static files for development. Labels are matched to clusters
based on semantic similarity using the same embedding model as flowcharts.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
d454aea0ab