Reject duplicate guest documents by hash

src/main/kotlin/com/android/trisolarisserver/models/booking/GuestDocument.kt

@@ -44,6 +44,9 @@ class GuestDocument(
     @Column(name = "storage_path", nullable = false)
     var storagePath: String,
 
+    @Column(name = "file_hash")
+    var fileHash: String? = null,
+
     @Column(name = "extracted_data", columnDefinition = "jsonb")
     @JdbcTypeCode(SqlTypes.JSON)
     var extractedData: String? = null,