feat(patterns): tutorial system

frontend/src/lib/api.ts

@@ -2,6 +2,7 @@ import type {
   CategoryListResponse,
   Pattern,
   PatternListResponse,
+  PatternTutorial,
   QuestionDetail,
   QuestionListResponse,
   Stats,
@@ -98,6 +99,10 @@ export async function getPattern(slug: string): Promise<Pattern> {
   return fetchApi<Pattern>(`/api/patterns/${slug}`);
 }
 
+export async function getPatternTutorial(slug: string): Promise<PatternTutorial> {
+  return fetchApi<PatternTutorial>(`/api/patterns/${slug}/tutorial`);
+}
+
 export async function getStats(): Promise<Stats> {
   return fetchApi<Stats>("/api/stats");
 }