Report stalled agent lanes and bound health lock waits

src/lib/hosts.ts

@@ -35,6 +35,21 @@ export interface HostAgentUpdate {
     checkedAt?: string;
 }
 
+export interface HostAgentLane {
+    name: 'health-1' | 'health-2' | 'read' | 'write';
+    alive: boolean; busy: boolean; lastPollAt: string | null; pollAgeSeconds: number;
+}
+export function hostAgentLaneLabel(name: HostAgentLane['name']): string {
+    return { 'health-1': 'Health check 1', 'health-2': 'Health check 2', read: 'File reads', write: 'Actions' }[name];
+}
+export function hostAgentLaneState(lane: HostAgentLane): 'stopped' | 'stalled' | 'busy' | 'starting' | 'polling' {
+    if (!lane.alive) return 'stopped';
+    // Reads and mutations can legitimately take minutes. Health work has a
+    // bounded budget; an old poll there indicates a blocked worker even if busy.
+    if (lane.pollAgeSeconds > 90 && (!lane.busy || lane.name.startsWith('health-'))) return 'stalled';
+    return lane.busy ? 'busy' : lane.lastPollAt === null ? 'starting' : 'polling';
+}
+
 export function hostAgentUpdatesEnabled(inventory: HostInventory): boolean {
     return inventory.agentUpdate?.enabled === true && inventory.capabilities?.includes('agent.update') === true;
 }
@@ -68,6 +83,7 @@ export interface HostInventory {
     currentOperation?: string | null; [key: string]: unknown;
     capabilities?: string[];
     agentUpdate?: HostAgentUpdate;
+    agentLanes?: HostAgentLane[];
     instanceResources?: InstanceResources[];
     instanceResourcesError?: string;
     instanceStates?: InstanceState[];