fix: harden AI analysis and seed defaults

modules/ai/types.test.ts

@@ -51,7 +51,7 @@ const validAnalysisOutput: ElderAiAnalysisOutput = {
   modelSummary: {
     provider: "openai-compatible",
     chatModel: "gpt-test",
-    embeddingModel: "embedding-test",
+    knowledgeRetrieval: "keyword",
   },
 };
 
@@ -142,6 +142,13 @@ describe("AI validators", () => {
           modelSummary: { ...validAnalysisOutput.modelSummary, provider: "anthropic" },
         },
       },
+      {
+        name: "unexpected knowledge retrieval mode",
+        value: {
+          ...validAnalysisOutput,
+          modelSummary: { ...validAnalysisOutput.modelSummary, knowledgeRetrieval: "embedding" },
+        },
+      },
       {
         name: "non-finite confidence",
         value: { ...validAnalysisOutput, confidence: "not-a-number" },