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:

unshackle/core/tracks/attachment.py

@@ -10,6 +10,7 @@ from zlib import crc32
 import requests
 
 from unshackle.core.config import config
+from unshackle.core.constants import DOWNLOAD_LICENCE_ONLY
 
 
 class Attachment:
@@ -43,6 +44,8 @@ class Attachment:
         if path is None and url is None:
             raise ValueError("Either path or url must be provided.")
 
+        self.url = url
+
         if url:
             if not isinstance(url, str):
                 raise ValueError("The attachment URL must be a string.")
@@ -57,7 +60,10 @@ class Attachment:
 
             download_path = config.directories.temp / file_name
 
-            # Download the file
+            # Download the file unless we're in license-only mode
+            if DOWNLOAD_LICENCE_ONLY.is_set():
+                path = None
+            else:
                 try:
                     session = session or requests.Session()
                     response = session.get(url, stream=True)
@@ -73,25 +79,30 @@ class Attachment:
                 except Exception as e:
                     raise ValueError(f"Failed to download attachment from URL: {e}")
 
-        if not isinstance(path, (str, Path)):
+        if path is not None and not isinstance(path, (str, Path)):
             raise ValueError("The attachment path must be provided.")
 
+        if path is not None:
             path = Path(path)
             if not path.exists():
                 raise ValueError("The attachment file does not exist.")
 
+        if path is not None:
             name = (name or path.stem).strip()
+        else:
+            name = (name or Path(file_name).stem).strip()
         mime_type = (mime_type or "").strip() or None
         description = (description or "").strip() or None
 
         if not mime_type:
+            suffix = path.suffix.lower() if path is not None else Path(file_name).suffix.lower()
             mime_type = {
                 ".ttf": "application/x-truetype-font",
                 ".otf": "application/vnd.ms-opentype",
                 ".jpg": "image/jpeg",
                 ".jpeg": "image/jpeg",
                 ".png": "image/png",
-            }.get(path.suffix.lower(), mimetypes.guess_type(path)[0])
+            }.get(suffix, mimetypes.guess_type(file_name if path is None else path)[0])
             if not mime_type:
                 raise ValueError("The attachment mime-type could not be automatically detected.")
 
@@ -111,11 +122,16 @@ class Attachment:
     @property
     def id(self) -> str:
         """Compute an ID from the attachment data."""
+        if self.path and self.path.exists():
             checksum = crc32(self.path.read_bytes())
+        elif self.url:
+            checksum = crc32(self.url.encode("utf8"))
+        else:
+            checksum = crc32(self.name.encode("utf8"))
         return hex(checksum)
 
     def delete(self) -> None:
-        if self.path:
+        if self.path and self.path.exists():
             self.path.unlink()
         self.path = None