The tasks/notes/projects/habits/domains tables all have a tsvector
search_vector column and a GIN index, but nothing was populating it.
GET /api/search returned zero results for every query.
This migration adds a BEFORE INSERT OR UPDATE trigger on each of the
five searchable tables. The trigger function uses to_tsvector with
the appropriate title + description/content columns and is named
project_e_search_vector_<table>_update. Drops any pre-existing trigger
of the same name so re-running the migration is safe.
Backfills 64 existing rows.
Parent: t_e1cbd87d