fix(dashboard): cut duplicate API/icon spam, lazy-load provider assets

Share one /api/models fetch via useModelCaps cache, mount ModelSelectModal
only when open, stop double fetchModelAliases on CLI tool cards, and resolve
provider icons through a session 404 cache with missing PNGs + loading=lazy.
Also include Claude Exa MCP toggle (claude-settings + ClaudeToolCard) that
was already in the working tree.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/shared/utils/index.js

@@ -1,6 +1,7 @@
 // Shared Utils - Export all
 export { cn } from "./cn";
 export * as api from "./api";
+export { getProviderIconSrc, markProviderIconMissing, resolveProviderIconId } from "./providerIcon";
 
 import { v4 as uuidv4 } from "uuid";
 

src/shared/utils/providerIcon.js

@@ -0,0 +1,40 @@
+// Provider icon paths under /public/providers.
+// Alias related brands; session-cache 404s so one miss never spams again.
+
+const ICON_ALIASES = {
+  "perplexity-agent": "perplexity",
+  "gitlab-duo": "gitlab",
+  "vercel-ai-gateway": "vercel",
+};
+
+// Runtime only — first 404 remembers id for the whole session
+const failedIds = new Set();
+
+function normalizeId(providerId) {
+  if (!providerId || typeof providerId !== "string") return "";
+  return providerId.trim().toLowerCase();
+}
+
+/** Resolve icon file id (after alias). Empty if previously failed this session. */
+export function resolveProviderIconId(providerId) {
+  const id = normalizeId(providerId);
+  if (!id) return "";
+  if (failedIds.has(id)) return "";
+  const aliased = ICON_ALIASES[id] || id;
+  if (failedIds.has(aliased)) return "";
+  return aliased;
+}
+
+/** `/providers/{id}.png` or null when previously failed. */
+export function getProviderIconSrc(providerId) {
+  const id = resolveProviderIconId(providerId);
+  return id ? `/providers/${id}.png` : null;
+}
+
+/** Call from img onError so later mounts skip the request. */
+export function markProviderIconMissing(providerId) {
+  const id = normalizeId(providerId);
+  if (id) failedIds.add(id);
+  const aliased = ICON_ALIASES[id];
+  if (aliased) failedIds.add(aliased);
+}