release: v1.2.0 Production GA (single-node)

- known-limitations, deployment runbook, release checklist
- prod compose requires JWT secret; BARADB_ENV=production fail-closed
- scripts/backup-restore-drill.sh (backup → wipe → restore → verify)
- version bump 1.2.0 (nimble, Dockerfile, health, CHANGELOG dated)

docs/bg/known-limitations.md

@@ -0,0 +1,33 @@
+# Известни ограничения — v1.2.0 Production GA
+
+| Ниво | Значение |
+|------|----------|
+| **Supported (GA)** | Документирано, тествано, подходящо за prod в обхвата |
+| **Experimental** | Работи в тестове/demo; не е HA SLA |
+| **Not supported** | Извън обхват |
+
+## Матрица
+
+| Област | GA (v1.2.0) | Experimental / по-късно |
+|--------|-------------|-------------------------|
+| Single-node SQL + LSM | **Supported** | — |
+| Schema / FTS / HNSW / graphs persist | **Supported** | — |
+| Auth + JWT (когато е конфигуриран) | **Supported** | — |
+| Backup / restore | **Supported** | — |
+| Multi-DB (без Raft) | **Supported** | — |
+| Raft 3-node + SQL/DDL | **Experimental** | InstallSnapshot, membership |
+| Raft multi-DB | **Not supported** | само `default` |
+| Follower linearizable reads | **Not supported** | best-effort след apply |
+| ORC multi-thread shared LSM | **Not supported** | ARC по подразбиране |
+
+## GA (single-node)
+
+Crash recovery с WAL, schema/index persist, `/health` + `/metrics`, offline backup/restore.
+
+## Raft
+
+Виж [distributed.md](distributed.md). Staging/ops, **не** v1.2.0 HA продукт.
+
+## Виж също
+
+- [Deployment](deployment.md) · [Backup](backup.md) · [en limitations](../en/known-limitations.md)