feat(remote): PeerTube browse passthroughs on RemoteClientKind

pt_channels/pt_channel_videos/pt_video_media/pt_watch_url dispatch to the
PeerTubeClient; Err for a catacomb remote. RemoteChannelInfo now Serialize.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/peertube.rs

@@ -24,8 +24,7 @@ struct OAuthTokens {
 }
 
 /// One channel in a PeerTube target's channel list.
-#[derive(Clone, Debug, PartialEq)]
-#[allow(dead_code)] // consumed by the browse UI in phase 3
+#[derive(Clone, Debug, PartialEq, serde::Serialize)]
 pub struct RemoteChannelInfo {
     pub handle: String,
     pub display_name: String,

src/remote.rs

@@ -187,6 +187,30 @@ impl RemoteClientKind {
             Self::Peertube(_) => crate::config::RemoteKind::Peertube,
         }
     }
+    pub fn pt_channels(&self) -> Result<Vec<crate::peertube::RemoteChannelInfo>, String> {
+        match self {
+            Self::Peertube(p) => p.list_channels(),
+            Self::Catacomb(_) => Err("not a PeerTube remote".into()),
+        }
+    }
+    pub fn pt_channel_videos(&self, handle: &str, page: usize) -> Result<Vec<RemoteVideo>, String> {
+        match self {
+            Self::Peertube(p) => p.channel_videos(handle, page),
+            Self::Catacomb(_) => Err("not a PeerTube remote".into()),
+        }
+    }
+    pub fn pt_video_media(&self, uuid: &str) -> Result<Option<String>, String> {
+        match self {
+            Self::Peertube(p) => p.video_media(uuid),
+            Self::Catacomb(_) => Err("not a PeerTube remote".into()),
+        }
+    }
+    pub fn pt_watch_url(&self, uuid: &str) -> Result<String, String> {
+        match self {
+            Self::Peertube(p) => Ok(p.watch_url(uuid)),
+            Self::Catacomb(_) => Err("not a PeerTube remote".into()),
+        }
+    }
 }
 
 /// Whether a relative URL points at peer media the read-only feed token grants
@@ -329,4 +353,18 @@ mod tests {
         assert_eq!(b.kind(), RemoteKind::Peertube);
         assert_eq!(b.name(), "p");
     }
+
+    #[test]
+    fn peertube_passthroughs_reject_catacomb() {
+        use crate::config::{RemoteKind, RemoteSection};
+        let cat = RemoteSection {
+            name: "c".into(), url: "http://p:8081".into(),
+            kind: RemoteKind::Catacomb, username: None, password: None,
+        };
+        let k = RemoteClientKind::from_section(&cat);
+        assert!(k.pt_channels().is_err());
+        assert!(k.pt_channel_videos("h", 0).is_err());
+        assert!(k.pt_video_media("u").is_err());
+        assert!(k.pt_watch_url("u").is_err());
+    }
 }