Fixed: ChannelImporter skips channel set dirs without JSON manifest

When a channel package directory exists but contains only __pycache__
artifacts (e.g. stale bytecode, unfinished channel), the importer
would crash with FileNotFoundError trying to load the missing JSON.
Add an isfile() guard to silently skip incomplete channel set dirs.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>

Author: oliv3r

resources/lib/helpers/channelimporter.py

@@ -160,6 +160,9 @@ def get_channels(self, include_disabled=False, **kwargs):  # NOSONAR
                     continue
 
                 channel_set_info_path = os.path.join(channel_set_path, "chn_{}.json".format(channel_set))
+                if not os.path.isfile(channel_set_info_path):
+                    Logger.warning(f"Skipping channel set '{channel_set}', no manifest found at: {channel_set_info_path}")
+                    continue
                 channel_infos = ChannelInfo.from_json(channel_set_info_path)
 
                 # Check if the channel was updated