feat(desktop): integrate SaaS llm_routing, template API, and onboarding template selection

- Add AgentTemplateAvailable/AgentTemplateFull types and fetchAvailableTemplates/fetchTemplateFull API methods to saas-client
- Add llm_routing field to SaaSAccountInfo for admin-configured routing priority
- Add availableTemplates state and fetchAvailableTemplates action to saasStore with background fetch on login
- Add admin llm_routing priority check in connectionStore connect() to force relay or local mode
- Add createFromTemplate action to agentStore with SOUL.md persistence
- Add Step 0 template selection to AgentOnboardingWizard with grid layout for template browsing

desktop/src/store/saasStore.ts

@@ -26,6 +26,7 @@ import {
   type SaaSLoginResponse,
   type TotpSetupResponse,
   type SyncConfigRequest,
+  type AgentTemplateAvailable,
 } from '../lib/saas-client';
 import { createLogger } from '../lib/logger';
 import {
@@ -70,6 +71,8 @@ export interface SaaSStateSlice {
   totpSetupData: TotpSetupResponse | null;
   /** Whether SaaS backend is currently reachable */
   saasReachable: boolean;
+  /** Agent templates available for onboarding */
+  availableTemplates: AgentTemplateAvailable[];
   /** Consecutive heartbeat/health-check failures */
   _consecutiveFailures: number;
   _heartbeatTimer?: ReturnType<typeof setInterval>;
@@ -86,6 +89,7 @@ export interface SaaSActionsSlice {
   syncConfigFromSaaS: () => Promise<void>;
   pushConfigToSaaS: () => Promise<void>;
   registerCurrentDevice: () => Promise<void>;
+  fetchAvailableTemplates: () => Promise<void>;
   clearError: () => void;
   restoreSession: () => void;
   setupTotp: () => Promise<TotpSetupResponse>;
@@ -140,6 +144,7 @@ export const useSaaSStore = create<SaaSStore>((set, get) => {
     totpRequired: false,
     totpSetupData: null,
     saasReachable: true,
+    availableTemplates: [],
     _consecutiveFailures: 0,
 
     // === Actions ===
@@ -189,6 +194,11 @@ export const useSaaSStore = create<SaaSStore>((set, get) => {
           log.warn('Failed to register device:', err);
         });
 
+        // Fetch available templates in background (non-blocking)
+        get().fetchAvailableTemplates().catch((err: unknown) => {
+          log.warn('Failed to fetch templates after login:', err);
+        });
+
         // Fetch available models in background (non-blocking)
         get().fetchAvailableModels().catch((err: unknown) => {
           log.warn('Failed to fetch models after login:', err);
@@ -587,6 +597,16 @@ export const useSaaSStore = create<SaaSStore>((set, get) => {
       }
     },
 
+    fetchAvailableTemplates: async () => {
+      try {
+        const templates = await saasClient.fetchAvailableTemplates();
+        set({ availableTemplates: templates });
+      } catch {
+        // Graceful degradation - don't block login
+        set({ availableTemplates: [] });
+      }
+    },
+
     clearError: () => {
       set({ error: null });
     },