Add automatic agent updates with verified rollback

src/lib/hosts.ts

@@ -24,6 +24,40 @@ export function hostDeletionMessage(host: Pick<Host, 'connected' | 'decommission
 }
 
 export interface HostLibrary { id: string; state: 'missing' | 'downloading' | 'verifying' | 'ready' | 'failed' | 'outdated'; progress?: number; error?: string }
+export interface HostAgentUpdate {
+    enabled: boolean;
+    state: 'current' | 'checking' | 'deferred' | 'updating' | 'updated' | 'failed';
+    currentVersion: string;
+    targetVersion?: string;
+    error?: string;
+    checkedAt?: string;
+}
+
+export function hostAgentUpdatesEnabled(inventory: HostInventory): boolean {
+    return inventory.agentUpdate?.enabled === true && inventory.capabilities?.includes('agent.update') === true;
+}
+
+export function hostAgentUpdateLabel(inventory: HostInventory): string {
+    if (!hostAgentUpdatesEnabled(inventory)) return 'Setup required';
+    const update = inventory.agentUpdate!;
+    if (update.state === 'current' && !update.checkedAt) return 'Awaiting first check';
+    return { current: 'Current', checking: 'Checking', deferred: 'Deferred',
+        updating: 'Updating', updated: 'Updated', failed: 'Needs attention' }[update.state];
+}
+
+export function hostAgentUpdateMessage(inventory: HostInventory): string {
+    if (!hostAgentUpdatesEnabled(inventory)) return 'Run the current installer once on this host to enable automatic agent updates.';
+    const update = inventory.agentUpdate!;
+    switch (update.state) {
+        case 'current': return update.checkedAt ? 'The last check found no newer compatible agent release.' : 'The host timer will check for a compatible agent release automatically.';
+        case 'checking': return 'The host is checking the controller release and verifying its download.';
+        case 'deferred': return 'The updater is waiting for the reported condition to clear. The host checks again automatically.';
+        case 'updating': return 'The host is replacing agent code and checking that the new process connects successfully.';
+        case 'updated': return 'The new agent connected successfully. Automatic checks continue.';
+        case 'failed': return 'The update did not complete successfully. Review the reported error before retrying setup.';
+    }
+}
+
 export interface HostInventory {
     hostname?: string; agentVersion?: string; protocolVersion?: number; os?: string; architecture?: string;
     cpu?: string; cpuCount?: number; memoryTotal?: number; memoryAvailable?: number;
@@ -31,6 +65,7 @@ export interface HostInventory {
     directoriesWritable?: boolean; runtimeImages?: string[]; libraries?: HostLibrary[];
     currentOperation?: string | null; [key: string]: unknown;
     capabilities?: string[];
+    agentUpdate?: HostAgentUpdate;
 }
 export interface Host {
     id: string; name: string; hostname: string; mode: HostMode; portMin: number; portMax: number;