feat(ai-settings): show remaining free MIND allotment

src/components/AiSettings.tsx

@@ -152,8 +152,14 @@ export function AiSettings({ webid }: { webid: string | null }) {
     if (!data) return null;
     if (data.summary.source === "user-pref")
       return `Right now your apps are built with ${data.summary.providerLabel} · ${data.summary.model}.`;
-    if (data.summary.source === "env-fallback")
+    if (data.summary.source === "env-fallback") {
+      const free = data.freeBalance;
+      if (typeof free === "number" && free <= 0)
+        return "You’ve used your free AI allotment. Add your own key below to keep building.";
+      if (typeof free === "number")
+        return `Right now your apps are built with the free built-in AI — ${free} free MIND left. Add your own key for a faster, smarter AI.`;
       return "Right now your apps are built with the free built-in AI.";
+    }
     return "No AI is set up yet — add a key below to start building.";
   })();
 

src/lib/builder/bridge-client.ts

@@ -298,6 +298,12 @@ export type AiSettings = {
   providers: AiConfiguredProvider[];
   pref: AiPref;
   summary: AiSummary;
+  /**
+   * Remaining free MIND allotment, when the coder would run on the bridge's
+   * built-in key and the ledger is on. null when on the user's own key or the
+   * ledger is off — render the source-based copy unchanged.
+   */
+  freeBalance?: number | null;
   catalog: AiCatalogEntry[];
 };