fix: export icon from viewer.js, import syncVaultSelectors in config.js, cleanup dupes

frontend/js/config.js

@@ -1,6 +1,7 @@
 // config.js — extracted from app.js (3872-4865)
 import { api } from './auth.js';
 import { state } from './state.js';
+import { syncVaultSelectors, setSelectedVaultContext, refreshSidebarForContext, loadVaults, loadTags } from './sidebar.js';
 import {  escapeHtml, safeCreateIcons } from './utils.js';
 
 let _recentTimestampTimer = null;

frontend/js/sidebar.js

@@ -3,7 +3,7 @@ import { safeCreateIcons, getFileIcon } from './utils.js';
 import { api } from './auth.js';
 import { populateCustomDropdown } from './ui.js';
 import { _populateRecentVaultFilter } from './config.js';
-import { el } from './viewer.js';
+import { el, icon } from './viewer.js';
 
 // ---------------------------------------------------------------------------
 // Vault context switching

frontend/js/viewer.js

@@ -622,7 +622,7 @@ export function el(tag, attrs, children) {
   return e;
 }
 
-function icon(name, size) {
+export function icon(name, size) {
   const i = document.createElement("i");
   i.setAttribute("data-lucide", name);
   i.style.width = size + "px";