feat(phase-39): role-based access control overhaul + forced password change

- Add must_change_password field to User model with migration b023

- Add POST /auth/change-password endpoint with password policy validation

- Add require_password_changed dependency to block requests until password is changed

- Add ChangePasswordModal with live password policy checklist (forced on first login)

- Show password policy in CreateUserModal and EditUserModal

- Fix backend permissions: tests, campaigns, templates, reports, evidence, worklogs

- red_tech/blue_tech: execute only, cannot create tests/campaigns/templates

- red_lead/blue_lead: create/edit tests/campaigns/templates, generate reports, no system access

- viewer: read-only everywhere, can generate reports

- Fix frontend role checks across TestDetailPage, TestDetailHeader, TeamTabs, TestsPage, CampaignsPage, CampaignDetailPage, Sidebar

frontend/src/context/AuthContext.tsx

@@ -12,6 +12,7 @@ import {
   getMe,
 } from "../api/auth";
 import type { User } from "../types/models";
+import ChangePasswordModal from "../components/ChangePasswordModal";
 
 /* ── Context shape ────────────────────────────────────────────────── */
 
@@ -31,18 +32,20 @@ export function AuthProvider({ children }: { children: ReactNode }) {
   const [user, setUser] = useState<User | null>(null);
   const [isLoading, setIsLoading] = useState(true);
 
-  // On mount — try to hydrate the user from the existing HttpOnly cookie.
-  // If no valid cookie exists the /auth/me call will 401 and we stay
-  // unauthenticated — no localStorage involved.
-  useEffect(() => {
-    getMe()
-      .then(setUser)
-      .catch(() => setUser(null))
-      .finally(() => setIsLoading(false));
+  const refreshUser = useCallback(async () => {
+    try {
+      const me = await getMe();
+      setUser(me);
+    } catch {
+      setUser(null);
+    }
   }, []);
 
+  useEffect(() => {
+    refreshUser().finally(() => setIsLoading(false));
+  }, [refreshUser]);
+
   const login = useCallback(async (username: string, password: string) => {
-    // The backend sets the HttpOnly cookie automatically
     await apiLogin(username, password);
     const me = await getMe();
     setUser(me);
@@ -53,6 +56,8 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     setUser(null);
   }, []);
 
+  const mustChangePassword = user?.must_change_password === true;
+
   return (
     <AuthContext.Provider
       value={{
@@ -64,6 +69,9 @@ export function AuthProvider({ children }: { children: ReactNode }) {
       }}
     >
       {children}
+      {mustChangePassword && (
+        <ChangePasswordModal isForced onSuccess={refreshUser} />
+      )}
     </AuthContext.Provider>
   );
 }