experiment(confidence-engine): route UI journey provider centrally

app/api/focused-investigation/deconstruct/route.js

@@ -1,4 +1,4 @@
-import { getProvider } from "@/lib/llm/provider";
+import { getProvider, getProviderModelName } from "@/lib/llm/provider";
 import {
   buildFocusedDeconstructPrompt,
   focusedDeconstructJsonSchema,
@@ -58,7 +58,7 @@ export async function POST(request) {
     const startedAt = Date.now();
     const wrapper = await provider.generateReconstruction(
       prompt,
-      process.env.OLLAMA_MODEL,
+      getProviderModelName(),
       focusedDeconstructJsonSchema,
     );
     const elapsedMs = Date.now() - startedAt;