refactor(application): strip comments, DRY ownership check + parse_content_type

crates/application/src/channels/queries.rs

@@ -1,14 +1,11 @@
 use uuid::Uuid;
 
-/// Fetch a single channel by ID.
 pub struct GetChannelQuery {
     pub channel_id: Uuid,
 }
 
-/// List all channels.
 pub struct ListChannelsQuery;
 
-/// List channels belonging to a specific owner.
 pub struct ListByOwnerQuery {
     pub owner_id: Uuid,
 }