fix(dl): prevent attachment downloads during --skip-dl

Set DOWNLOAD_LICENCE_ONLY earlier in the download command so services build tracks in license-only mode.

Update Attachment URL handling to avoid eager downloads in license-only mode while keeping metadata, stable IDs, and safe cleanup behavior.

unshackle/commands/dl.py

@@ -897,6 +897,9 @@ class dl:
         self.search_source = None
         start_time = time.time()
 
+        if skip_dl:
+            DOWNLOAD_LICENCE_ONLY.set()
+
         if not acodec:
             acodec = []
         elif isinstance(acodec, Audio.Codec):
@@ -1577,9 +1580,6 @@ class dl:
 
             dl_start_time = time.time()
 
-            if skip_dl:
-                DOWNLOAD_LICENCE_ONLY.set()
-
             try:
                 with Live(Padding(download_table, (1, 5)), console=console, refresh_per_second=5):
                     with ThreadPoolExecutor(downloads) as pool: