docs(roadmap): merge lineage + FK cascade в единый epic с design draft

Объединил два отдельных backlog item'а (Lineage / dependency graph + Cross-
dictionary FK с cascade rules) в один epic "Dictionary relationships v2" —
они complementary halves: lineage = read-side (discovery), cascade = write-side
(close semantics). Operate over same FK metadata, удобнее spec'ить вместе.

Design DRAFT 318 строк / 15KB:
- 3 stakeholder pain points (data stewards, Альтум consumers, schema editors)
- IN scope: A (lineage discovery 4 endpoints+UI), B (cascade rules block/warn/cascade), C (cross-cutting outbox+SLO)
- OUT scope (defer): schema-time validation, graph viz, multi-hop, cross-bundle
- 3 architecture options per area + recommendation (A=in-memory+MV hybrid, B=sync для v2)
- 4 D-questions для plan-eng-review
- 3 pre-code assignment items (Альтум behavior, UX preference, bundle versioning)
- 4-phase implementation (3-5 нед CC total)
- 4 risks + mitigations
- Success criteria с конкретными SLO targets

docs/status/2026-05-07-state.md

@@ -131,8 +131,7 @@
 
 - **Approval workflow v2** (draft → review → publish) — design doc сохранён в `~/.gstack/projects/claude/zimin-main-design-approval-workflow-v2-20260507-121632.md`. Defer'нут до prod LIVE + observed compliance needs. Re-evaluate через 1-2 месяца после Альтум stable.
 - **True HA Postgres** (3-instance + Longhorn + external Yandex S3) — отдельный future epic для multi-node cluster, не для cluster.142
-- Lineage / dependency graph между dictionaries
-- Cross-dictionary FK с cascade rules
+- **Dictionary relationships v2** — combine lineage / dependency graph + cross-dictionary FK cascade rules в один epic. Design DRAFT в `~/.gstack/projects/claude/zimin-main-design-dict-relationships-v2-20260507-230237.md` (3-5 нед CC, 4 phases, 4 D-questions для plan-eng-review). Pre-code assignment: Альтум consumer behavior на cascade events.
 - Data quality rules engine
 - Federation MDM-кластеров (master/replica)
 - Schema registry (Apicurio/Confluent) для Kafka