fix write file (#103)

apps/web/app/api/docs-chat/route.ts

@@ -23,6 +23,7 @@ You have access to the full json-render documentation via the bash and readFile
 When answering questions:
 - Use the bash tool to list files (ls /workspace/docs/) or search for content (grep -r "keyword" /workspace/docs/)
 - Use the readFile tool to read specific documentation pages (e.g. readFile with path "/workspace/docs/index.md")
+- Do NOT use bash to write, create, modify, or delete files (no tee, cat >, sed -i, echo >, cp, mv, rm, mkdir, touch, etc.) — you are read-only
 - Always base your answers on the actual documentation content
 - Be concise and accurate
 - If the docs don't cover a topic, say so honestly
@@ -107,14 +108,19 @@ export async function POST(req: Request) {
   const { messages }: { messages: UIMessage[] } = await req.json();
 
   const docsFiles = await loadDocsFiles();
-  const { tools } = await createBashTool({ files: docsFiles });
+  const {
+    tools: { bash, readFile },
+  } = await createBashTool({ files: docsFiles });
 
   const result = streamText({
     model: DEFAULT_MODEL,
     system: SYSTEM_PROMPT,
     messages: await convertToModelMessages(messages),
     stopWhen: stepCountIs(5),
-    tools,
+    tools: {
+      bash,
+      readFile,
+    },
     prepareStep: ({ messages: stepMessages }) => ({
       messages: addCacheControl(stepMessages),
     }),