Show each feed's id labelled in ipx list (#82)

The id led the title's line unlabelled, so antirez.com's, "feed" with no title beside it, read
as a heading; 'ipx fetch antirez' was tried instead and failed. The title now heads the entry and
the id has its own row.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main.rs

@@ -886,7 +886,10 @@ async fn list(ctx: &Ctx) -> Result<()> {
     }
     for (id, feed) in &cfg.feeds {
         let s = ctx.db.feed_summary(id).await?;
-        println!("{id}  {}", s.title.as_deref().unwrap_or("-"));
+        // The id on a line of its own, labelled: first on the title's line, antirez.com's id
+        // "feed" read as a heading and 'ipx fetch antirez' was tried instead (issue #82).
+        println!("{}", s.title.as_deref().filter(|t| !t.is_empty()).unwrap_or(id));
+        println!("    id           {id}");
         println!("    url          {}", feed.url);
         println!("    last checked {}", ago(s.last_checked));
         println!("    entries      {} ({} downloaded)", s.entries, s.downloaded);