fix(plugin): normalize bare schema refs

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin/normalize-tool-arg-schemas.ts

@@ -47,6 +47,14 @@ function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null && !Array.isArray(value)
 }
 
+function normalizeJsonSchemaRef(value: string): string {
+  if (value.startsWith("#") || value.includes(":") || value.startsWith("/")) {
+    return value
+  }
+
+  return `#/$defs/${value}`
+}
+
 export function sanitizeJsonSchema(value: unknown, depth = 0, isPropertyName = false): unknown {
   if (Array.isArray(value)) {
     return value.map((item) => sanitizeJsonSchema(item, depth + 1, false))
@@ -67,6 +75,11 @@ export function sanitizeJsonSchema(value: unknown, depth = 0, isPropertyName = f
       continue
     }
 
+    if (!isPropertyName && key === "$ref" && typeof nestedValue === "string") {
+      sanitized[key] = normalizeJsonSchemaRef(nestedValue)
+      continue
+    }
+
     const childIsPropertyName = key === "properties" && !isPropertyName
     sanitized[key] = sanitizeJsonSchema(nestedValue, depth + 1, childIsPropertyName)
   }