Phase 2 P4 partial-scope (head approved 2026-05-27 15:24). The full
drop of paliad.trigger_events + the legacy route + 5 read sites is
gated on an editorial backfill that's not in coder scope — 73 active
sequencing_rules carry proceeding_type_id IS NULL and are addressed
ONLY via trigger_event_id today. Dropping anything would break those
73 orphans.
What this lands:
1. Mig 156 — NULL out trigger_event_id on the 2 hybrid rules that
carry BOTH parent_id AND trigger_event_id. Per design §2.1 /
m's Q1, parent_id is the canonical predecessor link; the
hybrid trigger_event_id was redundant. The 2 rules' parent_id
chains keep the live edge. Live-DB verified post-apply: 0
active hybrid rules remain.
2. Deprecation + Link headers on POST /api/tools/event-deadlines
per RFC 8594 / RFC 9745. The route stays functional so the 73
orphans keep working until reparenting lands.
What this does NOT land (gated on editorial):
- DROP TABLE paliad.trigger_events
- DROP COLUMN paliad.sequencing_rules.trigger_event_id
- Remove the legacy /api/tools/event-deadlines handler
- Remove EventDeadlineService + ExportService::1680 sheet
- Remove deadline_rule_service.go:226 label-fallback path
- Remove event_type_service.go:40+414 reads (33 event_types still
reference trigger_event_id)
- Update cmd/gen-upc-snapshot/main.go:185-202 to skip trigger_events
- Drop the sequencing_rules_trigger_event_id_fkey FK
All of the above lands in a follow-up mig once the orphan count
hits zero. Comment to follow on m/paliad#149 with the editorial-
backlog list.
Verified: live-DB pre/post hybrid count (0 active hybrids remain);
mig idempotent; go vet clean.
Design: docs/design-deadline-system-revision-2026-05-27.md §2.1
(parent_id canonical), §3.4 (legacy route fate), §4.3 (table fate),
§5 (slice train P5 row). t-paliad-331.
mAi
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