guest docs: log errors

src/main/kotlin/com/android/trisolarisserver/controller/GuestDocuments.kt

@@ -31,6 +31,7 @@ import java.nio.file.Files
 import java.nio.file.Paths
 import java.util.UUID
 import java.security.MessageDigest
+import org.slf4j.LoggerFactory
 
 @RestController
 @RequestMapping("/properties/{propertyId}/guests/{guestId}/documents")
@@ -52,6 +53,7 @@ class GuestDocuments(
     @org.springframework.beans.factory.annotation.Value("\${storage.documents.aiBaseUrl:\${storage.documents.publicBaseUrl}}")
     private val aiBaseUrl: String
 ) {
+    private val logger = LoggerFactory.getLogger(GuestDocuments::class.java)
 
     @PostMapping
     @ResponseStatus(HttpStatus.CREATED)
@@ -220,8 +222,8 @@ class GuestDocuments(
                 document.extractedAt = OffsetDateTime.now()
                 guestDocumentRepo.save(document)
                 guestDocumentEvents.emit(propertyId, guestId)
-            } catch (_: Exception) {
-                // Keep upload successful even if AI extraction fails.
+            } catch (ex: Exception) {
+                logger.warn("Document extraction failed for documentId={}", document.id, ex)
             }
         }
     }