Add OTP sign-in option + Account Linking (#276)

* feat(accounts): allow linking email password
* feat(auth): add OTP sign-in
* refactor(accounts): remove 'sonner' dependency and update toast imports
* feat(supabase): enable analytics and configure database seeding
* feat(auth): update email templates and add OTP template
* feat(auth): add last sign in method hints
* feat(config): add devIndicators position to bottom-right
* feat(auth): implement comprehensive last authentication method tracking tests

packages/features/auth/src/utils/last-auth-method.ts

@@ -0,0 +1,71 @@
+'use client';
+
+import { isBrowser } from '@kit/shared/utils';
+
+// Key for localStorage
+const LAST_AUTH_METHOD_KEY = 'auth_last_method';
+
+// Types of authentication methods
+export type AuthMethod = 'password' | 'otp' | 'magic_link' | 'oauth';
+
+export interface LastAuthMethod {
+  method: AuthMethod;
+  provider?: string; // For OAuth providers (e.g., 'google', 'github')
+  email?: string; // Store email for method-specific hints
+  timestamp: number;
+}
+
+/**
+ * Save the last used authentication method to localStorage
+ */
+export function saveLastAuthMethod(authMethod: LastAuthMethod): void {
+  try {
+    localStorage.setItem(LAST_AUTH_METHOD_KEY, JSON.stringify(authMethod));
+  } catch (error) {
+    console.warn('Failed to save last auth method:', error);
+  }
+}
+
+/**
+ * Get the last used authentication method from localStorage
+ */
+export function getLastAuthMethod() {
+  if (!isBrowser()) {
+    return null;
+  }
+
+  try {
+    const stored = localStorage.getItem(LAST_AUTH_METHOD_KEY);
+
+    if (!stored) {
+      return null;
+    }
+
+    const parsed = JSON.parse(stored) as LastAuthMethod;
+
+    // Check if the stored method is older than 30 days
+    const thirtyDaysAgo = Date.now() - 30 * 24 * 60 * 60 * 1000;
+
+    if (parsed.timestamp < thirtyDaysAgo) {
+      localStorage.removeItem(LAST_AUTH_METHOD_KEY);
+
+      return null;
+    }
+
+    return parsed;
+  } catch (error) {
+    console.warn('Failed to get last auth method:', error);
+    return null;
+  }
+}
+
+/**
+ * Clear the last used authentication method from localStorage
+ */
+export function clearLastAuthMethod() {
+  try {
+    localStorage.removeItem(LAST_AUTH_METHOD_KEY);
+  } catch (error) {
+    console.warn('Failed to clear last auth method:', error);
+  }
+}