Mark all read on an OPML subscription

Marking the subscription read did nothing: its own row holds no entries.
read-all now resolves the feeds grouped under the id -- via
subscriptions(), so a child promoted to config is included -- and marks
those. Button sits before Unsubscribe, where every other feed keeps it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AdXho5tTkjFLeUXKbEjKBh

src/web.rs

@@ -660,7 +660,15 @@ async fn read_all(
     State(state): State<WebState>,
     Path(id): Path<String>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let n = state.ctx.db.mark_all_read(&id)?;
+    // A subscription's own row has no entries, so marking it read means everything under it.
+    let mut ids = vec![id.clone()];
+    ids.extend(
+        crate::subscriptions(&state.ctx)?
+            .into_iter()
+            .filter(|s| s.cfg.group.as_deref() == Some(id.as_str()))
+            .map(|s| s.id),
+    );
+    let n = state.ctx.db.mark_all_read(&ids)?;
     Ok(Json(serde_json::json!({ "marked": n })))
 }