Restore exclusive provider-first setup recovery

components/setup-cta.tsx

@@ -15,9 +15,10 @@
  * its own save), the same re-read pattern chat.tsx uses for "models".
  */
 
-import type { AuthKeyStatus } from "@/src/core";
+import { useEffect, useState } from "react";
+import { MODEL_SLOTS, type AuthKeyStatus } from "@/src/core";
 import { classifyKeys, type ProviderKeyInfo } from "@/components/settings/keys-section";
-import { useModelCatalog } from "@/components/model-picker";
+import { useModelCatalog } from "@/components/model-catalog";
 import type { ModelCatalogResponse } from "@/src/core";
 
 /** Pure: does a MODEL-PROVIDER key exist among the statuses? Reuses
@@ -32,6 +33,33 @@ export function hasProviderKey(
 	return classifyKeys(statuses, providers).providerRows.some((s) => s.present);
 }
 
+/** Completeness is saved identity, not current provider availability. */
+export function savedSlotsConfigured(slots: ModelCatalogResponse["slots"] | undefined): boolean {
+	return MODEL_SLOTS.every((slot) => !!slots?.[slot]?.model);
+}
+
+/** Keep the last known completeness during connection invalidation, but
+ * follow ordinary slot repairs as soon as their shared snapshot arrives. */
+export function useModelSetup(initialConfigured: boolean) {
+	const { catalog } = useModelCatalog();
+	const [lastConfigured, setLastConfigured] = useState(initialConfigured);
+	const configured = catalog ? savedSlotsConfigured(catalog.slots) : lastConfigured;
+	useEffect(() => { if (catalog) setLastConfigured(savedSlotsConfigured(catalog.slots)); }, [catalog]);
+	return { catalog, configured, zeroKeys: catalog ? !catalog.providers.some((p) => p.keyPresent) : false };
+}
+
+/** A known unavailable route needs an explicit replacement, never an
+ * automatic provider/model substitution. Unknown metadata defers to the
+ * server's admission gate instead of declaring a route disconnected. */
+export function selectedModelUnavailable(catalog: ModelCatalogResponse | undefined, selected: string | undefined): boolean {
+	return !!catalog && !!selected && !catalog.models.some((m) => `${m.provider}:${m.id}` === selected);
+}
+
+/** Reuse the ordinary control (also opened by the existing keyboard action). */
+export function openModelPicker(): void {
+	window.dispatchEvent(new CustomEvent("lh:kbd-open-model-picker"));
+}
+
 /** The zero-keys truth for the calling page: TRUE only after a
  *  successful read says no provider key exists (pending and failed
  *  reads render nothing — the pill must never flash on a gap, and a