Polish multi-agent response activity

Keep active agent state aligned with replies while making the activity pill clearer with avatars and profile-aware mention resolution.

Made-with: Cursor

desktop/src-tauri/src/managed_agents/runtime.rs

@@ -502,6 +502,11 @@ pub fn spawn_agent_child(
     command.env("SPROUT_ACP_AGENTS", record.parallelism.to_string());
     command.env("SPROUT_ACP_MULTIPLE_EVENT_HANDLING", "owner-interrupt");
     command.env("SPROUT_ACP_DEDUP", "queue");
+    // Desktop-managed channel agents should answer explicit @mentions from any
+    // channel member, not just the human who created the local process. The ACP
+    // harness still requires mention matching by default, so this does not make
+    // agents react to ordinary channel chatter.
+    command.env("SPROUT_ACP_RESPOND_TO", "anyone");
     command.env(
         "GOOSE_MODE",
         std::env::var("GOOSE_MODE").unwrap_or_else(|_| "auto".to_string()),

desktop/src-tauri/src/relay.rs

@@ -327,10 +327,38 @@ where
         return Err(relay_error_message(response).await);
     }
 
-    response
-        .json::<T>()
+    let status = response.status();
+    let url = response.url().clone();
+    let content_type = response
+        .headers()
+        .get(reqwest::header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .unwrap_or("unknown")
+        .to_string();
+    let body = response
+        .bytes()
         .await
-        .map_err(|error| format!("parse failed: {error}"))
+        .map_err(|error| format!("read response body failed: {error}"))?;
+
+    serde_json::from_slice::<T>(&body).map_err(|error| {
+        let snippet = String::from_utf8_lossy(&body)
+            .chars()
+            .take(240)
+            .collect::<String>()
+            .replace(['\n', '\r', '\t'], " ")
+            .trim()
+            .to_string();
+
+        if content_type.contains("text/html") && snippet.contains("Cloudflare Access") {
+            return format!(
+                "relay returned Cloudflare Access sign-in instead of JSON for {url}. Check the active workspace token or Cloudflare/WARP access."
+            );
+        }
+
+        format!(
+            "parse failed: {error}; relay returned {status} {content_type} for {url}: {snippet}"
+        )
+    })
 }
 
 pub async fn send_empty_request(request: reqwest::RequestBuilder) -> Result<(), String> {