feat(agent): Split agents into maintainable chunks

src/lib/agents/agentState.ts

@@ -0,0 +1,41 @@
+import { BaseMessage } from '@langchain/core/messages';
+import { Annotation, END } from '@langchain/langgraph';
+import { Document } from 'langchain/document';
+
+/**
+ * State interface for the agent supervisor workflow
+ */
+export const AgentState = Annotation.Root({
+  messages: Annotation<BaseMessage[]>({
+    reducer: (x, y) => x.concat(y),
+    default: () => [],
+  }),
+  query: Annotation<string>({
+    reducer: (x, y) => y ?? x,
+    default: () => '',
+  }),
+  relevantDocuments: Annotation<Document[]>({
+    reducer: (x, y) => x.concat(y),
+    default: () => [],
+  }),
+  bannedUrls: Annotation<string[]>({
+    reducer: (x, y) => x.concat(y),
+    default: () => [],
+  }),
+  searchInstructionHistory: Annotation<string[]>({
+    reducer: (x, y) => x.concat(y),
+    default: () => [],
+  }),
+  searchInstructions: Annotation<string>({
+    reducer: (x, y) => y ?? x,
+    default: () => '',
+  }),
+  next: Annotation<string>({
+    reducer: (x, y) => y ?? x ?? END,
+    default: () => END,
+  }),
+  analysis: Annotation<string>({
+    reducer: (x, y) => y ?? x,
+    default: () => '',
+  }),
+});