container row: pending-reminder count chip (⏰ N)

ContainerView gains pending_reminders: u64; computed during
build_all via Broker::count_pending_reminders_for, mapping
manager → MANAGER_AGENT recipient + sub-agents → logical name.
Updates on every rescan (mutation sites + crash_watch's 10s
poll); accept 10s staleness on background remind / scheduler
delivery — live updates on operator cancel via /api/state path.

client renders a small cyan chip on the row when the count > 0;
tooltip points the operator at the reminders section to view
or cancel.

hive-c0re/src/container_view.rs

@@ -29,6 +29,13 @@ pub struct ContainerView {
     /// for this agent's input.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub deployed_sha: Option<String>,
+    /// Count of this agent's pending reminders. Computed during
+    /// `build_all` via `Broker::count_pending_reminders_for`; the
+    /// dashboard renders a small chip when > 0. Updates with the
+    /// 10s `crash_watch` rescan + every container mutation site;
+    /// not real-time on remind/cancel-reminder but close enough.
+    #[serde(default)]
+    pub pending_reminders: u64,
 }
 
 /// Build the full container list. Wraps `lifecycle::list()` and
@@ -53,6 +60,20 @@ pub async fn build_all(coord: &Coordinator) -> Vec<ContainerView> {
         let deployed_sha = locked
             .get(&format!("agent-{logical}"))
             .map(|s| s[..s.len().min(12)].to_owned());
+        // Recipient name the broker uses for this agent — sub-agents
+        // are addressed by logical name, the manager by the
+        // MANAGER_AGENT constant. Mirrors the rest of the broker
+        // surface so the count matches what `mcp__hyperhive__remind`
+        // queued.
+        let reminder_recipient = if is_manager {
+            hive_sh4re::MANAGER_AGENT
+        } else {
+            logical.as_str()
+        };
+        let pending_reminders = coord
+            .broker
+            .count_pending_reminders_for(reminder_recipient)
+            .unwrap_or(0);
         out.push(ContainerView {
             port: lifecycle::agent_web_port(&logical),
             running: lifecycle::is_running(&logical).await,
@@ -62,6 +83,7 @@ pub async fn build_all(coord: &Coordinator) -> Vec<ContainerView> {
             needs_update,
             needs_login,
             deployed_sha,
+            pending_reminders,
         });
     }
     out