Search by meaning

Users search my <content> and keyword search misses results where they
used different words. Roughly <n> items.

Before building anything: at my size, would better keyword search fix
this more cheaply? Say so if it would.

If semantic search is right:
- Where do the vectors live, given my scale — a dedicated store, or a
  column in my existing database?
- What gets embedded: the whole item, or chunks?
- Combining with keyword search, so exact matches still rank first.
- Re-embedding when content changes, and the cost of that.

Then: 20 real queries I should test before and after, so I can tell
whether it actually improved.