perf(selfop): index staged observation joins and verify candidate builds

lastleg-service/src/test/java/com/baiyue/lastleg/schema/SelfoperatedAnalyticsSchemaContractTest.java

@@ -94,6 +94,16 @@ class SelfoperatedAnalyticsSchemaContractTest {
         assertTrue(ddl.get("ll_selfop_inventory_snapshot").contains("snapshot_run_id,source_account,customer_code,warehouse_code,sku_code,product_quality"));
     }
 
+    @Test
+    void factObservationLookupHasEqualityPrefixAndCoversProfileEvidence() throws Exception {
+        var ddl = tables(Files.readString(Path.of("src/main/resources/db/lastleg.sql")));
+        var stage = ddl.get("ll_selfop_sync_stage");
+        assertTrue(stage.contains("KEY idx_selfop_stage_fact_observation (observation_sequence,warehouse_code,object_type,validation_status,run_id,observed_at_utc)"));
+        // Observation lookup and business-key history serve different consumers; both are required.
+        assertTrue(stage.contains("KEY idx_selfop_stage_history (object_type,object_key_hash,stage_batch_id)"));
+        assertTrue(stage.contains("UNIQUE KEY uk_selfop_stage_object (stage_batch_id,object_type,object_key_hash)"));
+    }
+
     @Test
     void readAndSyncPermissionsAreIndependentWithThreeAuthorizedAdminMenus() throws Exception {
         var seed = Files.readString(Path.of("../iam/src/main/resources/db/selfoperated-analytics-permissions.sql"));