Frontend: structured error handling, state fixes, accessibility, i18n

- Enhance fetchWithAuth with auto-401, retry w/ exponential backoff, timeout
- Remove ~40 manual 401 checks across 10 feature files
- Fix state: brightness cache setter, manual edit flag resets, static import
- Add ARIA: role=dialog/tablist, aria-modal, aria-labelledby, aria-selected
- Add focus trapping in Modal base class, aria-expanded on hint toggles
- Fix WCAG AA color contrast with --primary-text-color variable
- Add i18n pluralization (CLDR rules for en/ru), getCurrentLocale export
- Replace hardcoded strings in dashboard.js and profiles.js
- Add data-i18n-aria-label support, 20 new keys in en.json and ru.json

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/js/features/profiles.js

@@ -3,7 +3,7 @@
  */
 
 import { apiKey, _profilesCache, set_profilesCache } from '../core/state.js';
-import { API_BASE, getHeaders, escapeHtml, handle401Error } from '../core/api.js';
+import { fetchWithAuth, escapeHtml } from '../core/api.js';
 import { t } from '../core/i18n.js';
 import { showToast, showConfirm } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
@@ -25,12 +25,13 @@ export async function loadProfiles() {
     if (!container) return;
 
     try {
-        const resp = await fetch(`${API_BASE}/profiles`, { headers: getHeaders() });
+        const resp = await fetchWithAuth('/profiles');
         if (!resp.ok) throw new Error('Failed to load profiles');
         const data = await resp.json();
         set_profilesCache(data.profiles);
         renderProfiles(data.profiles);
     } catch (error) {
+        if (error.isAuth) return;
         console.error('Failed to load profiles:', error);
         container.innerHTML = `<p class="error-message">${error.message}</p>`;
     }
@@ -72,7 +73,7 @@ function createProfileCard(profile) {
             }
             return `<span class="stream-card-prop">${c.condition_type}</span>`;
         });
-        const logicLabel = profile.condition_logic === 'and' ? ' AND ' : ' OR ';
+        const logicLabel = profile.condition_logic === 'and' ? t('profiles.logic.and') : t('profiles.logic.or');
         condPills = parts.join(`<span class="profile-logic-label">${logicLabel}</span>`);
     }
 
@@ -96,7 +97,7 @@ function createProfileCard(profile) {
                 </div>
             </div>
             <div class="card-subtitle">
-                <span class="card-meta">${profile.condition_logic === 'and' ? 'ALL' : 'ANY'}</span>
+                <span class="card-meta">${profile.condition_logic === 'and' ? t('profiles.logic.all') : t('profiles.logic.any')}</span>
                 <span class="card-meta">⚡ ${targetCountText}</span>
                 ${lastActivityMeta}
             </div>
@@ -128,7 +129,7 @@ export async function openProfileEditor(profileId) {
     if (profileId) {
         titleEl.textContent = t('profiles.edit');
         try {
-            const resp = await fetch(`${API_BASE}/profiles/${profileId}`, { headers: getHeaders() });
+            const resp = await fetchWithAuth(`/profiles/${profileId}`);
             if (!resp.ok) throw new Error('Failed to load profile');
             const profile = await resp.json();
 
@@ -167,7 +168,7 @@ export function closeProfileEditorModal() {
 async function loadProfileTargetChecklist(selectedIds) {
     const container = document.getElementById('profile-targets-list');
     try {
-        const resp = await fetch(`${API_BASE}/picture-targets`, { headers: getHeaders() });
+        const resp = await fetchWithAuth('/picture-targets');
         if (!resp.ok) throw new Error('Failed to load targets');
         const data = await resp.json();
         const targets = data.targets || [];
@@ -253,8 +254,7 @@ async function toggleProcessPicker(picker, row) {
     picker.style.display = '';
 
     try {
-        const resp = await fetch(`${API_BASE}/system/processes`, { headers: getHeaders() });
-        if (resp.status === 401) { handle401Error(); return; }
+        const resp = await fetchWithAuth('/system/processes');
         if (!resp.ok) throw new Error('Failed to fetch processes');
         const data = await resp.json();
 
@@ -326,7 +326,7 @@ export async function saveProfileEditor() {
 
     const name = nameInput.value.trim();
     if (!name) {
-        profileModal.showError('Name is required');
+        profileModal.showError(t('profiles.error.name_required'));
         return;
     }
 
@@ -342,10 +342,9 @@ export async function saveProfileEditor() {
     const isEdit = !!profileId;
 
     try {
-        const url = isEdit ? `${API_BASE}/profiles/${profileId}` : `${API_BASE}/profiles`;
-        const resp = await fetch(url, {
+        const url = isEdit ? `/profiles/${profileId}` : '/profiles';
+        const resp = await fetchWithAuth(url, {
             method: isEdit ? 'PUT' : 'POST',
-            headers: getHeaders(),
             body: JSON.stringify(body),
         });
         if (!resp.ok) {
@@ -354,9 +353,10 @@ export async function saveProfileEditor() {
         }
 
         profileModal.forceClose();
-        showToast(isEdit ? 'Profile updated' : 'Profile created', 'success');
+        showToast(isEdit ? t('profiles.updated') : t('profiles.created'), 'success');
         loadProfiles();
     } catch (e) {
+        if (e.isAuth) return;
         profileModal.showError(e.message);
     }
 }
@@ -364,13 +364,13 @@ export async function saveProfileEditor() {
 export async function toggleProfileEnabled(profileId, enable) {
     try {
         const action = enable ? 'enable' : 'disable';
-        const resp = await fetch(`${API_BASE}/profiles/${profileId}/${action}`, {
+        const resp = await fetchWithAuth(`/profiles/${profileId}/${action}`, {
             method: 'POST',
-            headers: getHeaders(),
         });
         if (!resp.ok) throw new Error(`Failed to ${action} profile`);
         loadProfiles();
     } catch (e) {
+        if (e.isAuth) return;
         showToast(e.message, 'error');
     }
 }
@@ -381,14 +381,14 @@ export async function deleteProfile(profileId, profileName) {
     if (!confirmed) return;
 
     try {
-        const resp = await fetch(`${API_BASE}/profiles/${profileId}`, {
+        const resp = await fetchWithAuth(`/profiles/${profileId}`, {
             method: 'DELETE',
-            headers: getHeaders(),
         });
         if (!resp.ok) throw new Error('Failed to delete profile');
-        showToast('Profile deleted', 'success');
+        showToast(t('profiles.deleted'), 'success');
         loadProfiles();
     } catch (e) {
+        if (e.isAuth) return;
         showToast(e.message, 'error');
     }
 }