feat: document user management system and RBAC implementation

- Update copilot-instructions.md with user model, API routes, and frontend patterns
- Update README.md with RBAC details, user management API, and security sections
- Add user management technical documentation to TECH-CHANGELOG.md
- Bump version to 2025.1.0-alpha.13 with user management changelog entries

dashboard/src/apiAuth.ts

@@ -31,6 +31,26 @@ export interface AuthCheckResponse {
   role?: string;
 }
 
+/**
+ * Change password for the currently authenticated user.
+ */
+export async function changePassword(currentPassword: string, newPassword: string): Promise<{ message: string }> {
+  const res = await fetch('/api/auth/change-password', {
+    method: 'PUT',
+    headers: { 'Content-Type': 'application/json' },
+    credentials: 'include',
+    body: JSON.stringify({ current_password: currentPassword, new_password: newPassword }),
+  });
+
+  const data = await res.json();
+
+  if (!res.ok) {
+    throw new Error(data.error || 'Failed to change password');
+  }
+
+  return data as { message: string };
+}
+
 /**
  * Authenticate a user with username and password.
  *