feat(speaking): add WordAnalysisItem type and extend SentenceEvaluation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/types/englishSpeaking.ts

@@ -136,6 +136,20 @@ export interface NextChallenge {
   suggestedMode?: string
 }
 
+export type WordErrorType =
+  | 'None'
+  | 'Mispronunciation'
+  | 'Omission'
+  | 'Insertion'
+  | 'UnexpectedBreak'
+  | 'MissingBreak'
+
+export interface WordAnalysisItem {
+  word: string
+  accuracyScore: number
+  errorType: WordErrorType
+}
+
 // 单句评价
 export interface SentenceEvaluation {
   id: string
@@ -156,6 +170,8 @@ export interface SentenceEvaluation {
     comment: string
     betterExpression: string
   }
+  wordAnalysis?: WordAnalysisItem[]
+  imageUrl?: string
 }
 
 // 整体评价报告