[aniketmandloi]: Verified on Neon: pgvector 0.8.6 enabled, migration recorded in `drizzle.__drizzle_migrations`, and `'[1,0]'::vector [=] '[0,1]'::vector` = 1.

Context: GitHub issue aniketmandloi/anything-tonight#5 (closed, 2 comments, reported 2026-09-24): ## Goal Vector column support for embeddings and mood vectors. ## Scope - Migration `CREATE EXTENSION IF NOT EXISTS vector` ## Acceptance criteria - [ ] Extension present in DB ## Verification `select * from pg_extension where extname='vector'` returns a row. ## Depends on #4 _Work in small atomic commits referencing this issue. See `docs/PLAN.md`._