fix(automation): enforce durable alert closure

Restore D037 durable incident readback without weakening database failure semantics.

Fence Agent99 dispatch and terminal learning to canonical identities, durable leases, verifier receipts, and reconciler-owned checkpoints.

Drain backup and restore legacy receipts in bounded cohorts with strict transport, claim, projection, and no-false-green controls.

Keep SSH service refusal visible while separating it from broker network-policy reachability.

apps/api/src/core/config.py

@@ -976,6 +976,39 @@ class Settings(BaseSettings):
         default=3.0,
         description="Timeout for fail-open Agent99 SRE alert relay POSTs.",
     )
+    ENABLE_BACKUP_RESTORE_LEGACY_BACKFILL: bool = Field(
+        default=True,
+        description=(
+            "Enable bounded durable BackupCheck replay for legacy backup/restore "
+            "Telegram receipt cards when a trusted Agent99 relay is configured."
+        ),
+    )
+    BACKUP_RESTORE_LEGACY_BACKFILL_STARTUP_SLEEP_SECONDS: float = Field(
+        default=5.0,
+        ge=0.0,
+        le=300.0,
+        description="Startup delay for the read-only legacy backup-card replay loop.",
+    )
+    BACKUP_RESTORE_LEGACY_BACKFILL_INTERVAL_SECONDS: float = Field(
+        default=15.0,
+        ge=5.0,
+        le=3600.0,
+        description="Interval between bounded legacy backup-card replay batches.",
+    )
+    BACKUP_RESTORE_LEGACY_BACKFILL_BATCH_LIMIT: int = Field(
+        default=20,
+        ge=1,
+        le=20,
+        description="Maximum legacy backup cards reserved and replayed per tick.",
+    )
+    BACKUP_RESTORE_LEGACY_BACKFILL_MAX_ROWS: int = Field(
+        default=100,
+        ge=1,
+        le=100,
+        description=(
+            "Maximum rows retained in one durable legacy replay snapshot cohort."
+        ),
+    )
     # 2026-04-24 Claude Sonnet 4.6 (ADR-095 WS4): Hermes NL 自然語言閘道
     # false=不啟用（預設），true=啟用 @mention 問答（需 ANTHROPIC_API_KEY）
     HERMES_NL_ENABLED: bool = Field(