fix(bd): V023 idempotent guard for SYSTEM_VERSIONING OFF (PRC-001)

Wrap 'ALTER TABLE ... SET SYSTEM_VERSIONING = OFF' in temporal_type=2 check.
Without this guard, re-running V023 on a DB where a previous partial run
already turned SYSTEM_VERSIONING OFF fails with:
  'SYSTEM_VERSIONING is not turned ON for table...'

Found while applying on SIGCM2 dev after a prior interrupted run. Now truly
idempotent: safe to re-run in any state (fully applied, never applied, or
partially applied with SYSTEM_VERSIONING already OFF).

database/migrations/V023__refactor_chargeable_char_config_to_product_type.sql

@@ -38,9 +38,17 @@ IF EXISTS (SELECT 1 FROM sys.tables WHERE name = 'ChargeableCharConfig' AND sche
 BEGIN
     PRINT 'V023: MedioId column found — proceeding with refactor.';
 
-    -- ─── 1. Turn OFF SYSTEM_VERSIONING ─────────────────────────────────
+    -- ─── 1. Turn OFF SYSTEM_VERSIONING (idempotent — skip if already OFF) ───
+    IF EXISTS (SELECT 1 FROM sys.tables
+               WHERE name = 'ChargeableCharConfig'
+                 AND schema_id = SCHEMA_ID('dbo')
+                 AND temporal_type = 2)  -- 2 = SYSTEM_VERSIONED_TEMPORAL_TABLE
+    BEGIN
         ALTER TABLE dbo.ChargeableCharConfig SET (SYSTEM_VERSIONING = OFF);
         PRINT 'V023: SYSTEM_VERSIONING = OFF.';
+    END
+    ELSE
+        PRINT 'V023: SYSTEM_VERSIONING already OFF — skipping.';
 
     -- ─── 2. Drop indexes that reference MedioId ────────────────────────
     IF EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'UX_ChargeableCharConfig_Vigente'