fix: harden AI analysis and seed defaults

modules/ai/types.ts

@@ -67,7 +67,7 @@ export type ElderAiRecommendation = {
 export type ElderAiModelSummary = {
   provider: "openai-compatible";
   chatModel: string;
-  embeddingModel: string;
+  knowledgeRetrieval: "keyword";
 };
 
 export type ElderAiAnalysisOutput = {
@@ -241,14 +241,14 @@ function validateModelSummary(value: unknown): ElderAiModelSummary | null {
   if (
     value.provider !== "openai-compatible" ||
     typeof value.chatModel !== "string" ||
-    typeof value.embeddingModel !== "string"
+    value.knowledgeRetrieval !== "keyword"
   ) {
     return null;
   }
   return {
     provider: "openai-compatible",
     chatModel: value.chatModel,
-    embeddingModel: value.embeddingModel,
+    knowledgeRetrieval: "keyword",
   };
 }