fix: ensure account manager initialized for count_tokens

- Add ensureInitialized() call before count_tokens handler
- Use hybrid approach: local estimation for text, API for images/docs
- This prevents "No accounts available" error on first request

src/cloudcode/count-tokens.js

@@ -278,7 +278,7 @@ export function createCountTokensHandler(accountManager) {
             const result = await countTokens(
                 { messages, model, system, tools, tool_choice, thinking },
                 accountManager,
-                { useAPI: true } // Use API for accurate token counting
+                { useAPI: false } // Use local estimation by default, API for complex content (images/docs)
             );
 
             res.json(result);