Replaces the original "migration advisory lock" sketch. Once processor
doesn't run DDL, the lock concern delegates to Directus's db-init runner.
Context: positions hypertable + faulty column DDL currently exists in
both processor (src/db/migrations/0001 + 0002) and directus
(db-init/001/002/003). Two sources of truth for the same schema is a
known hazard — adding a column means editing two files in two repos,
and silent drift between them is invisible until runtime.
Fix: directus becomes the sole DDL owner. Processor's migration runner
is retired; only INSERT/SELECT/UPDATE remain.
Task spec covers:
- Pre-flight diff between processor migrations and directus db-init
(must be byte/semantically equivalent before deletion)
- File-by-file deletion list
- Test infra migration (integration test moves to fixture-based schema
setup, matching the established Phase 1.5 task 1.5.6 pattern)
- Wiki + ROADMAP updates
- compose.yaml depends_on directus: service_healthy
- Operational notes (existing migrations_applied table is left in place)
Sequence: ideally lands AFTER Phase 1.5 ships so the agent shipping the
WS endpoint isn't pulled into a side quest mid-flight.
