implemented 15,12,18 didn't check 18

frontend/src/store/editorStore.ts

@@ -67,6 +67,7 @@ interface EditorActions {
   setHoveredWordIndex: (index: number | null) => void;
   deleteSelectedWords: () => void;
   deleteWordRange: (startIndex: number, endIndex: number) => void;
+  updateWordText: (index: number, text: string) => void;
   addCutRange: (start: number, end: number, trimGroupId?: string) => void;
   addMuteRange: (start: number, end: number) => void;
   addGainRange: (start: number, end: number, gainDb: number) => void;
@@ -262,6 +263,33 @@ export const useEditorStore = create<EditorState & EditorActions>()(
         get().addCutRange(words[startIndex].start, words[endIndex].end);
       },
 
+      updateWordText: (index, text) => {
+        const { words, segments } = get();
+        if (index < 0 || index >= words.length) return;
+        const newWords = words.map((w, i) =>
+          i === index ? { ...w, word: text } : w
+        );
+        // Also update the corresponding segment's words and text
+        let globalIdx = 0;
+        const newSegments = segments.map((seg) => {
+          const start = globalIdx;
+          globalIdx += seg.words.length;
+          if (index >= start && index < start + seg.words.length) {
+            const localIdx = index - start;
+            const updatedSegWords = seg.words.map((w, i) =>
+              i === localIdx ? { ...w, word: text } : w
+            );
+            return {
+              ...seg,
+              words: updatedSegWords,
+              text: updatedSegWords.map((w) => w.word).join(' '),
+            };
+          }
+          return seg;
+        });
+        set({ words: newWords, segments: newSegments });
+      },
+
       addCutRange: (start, end, trimGroupId) => {
         const { cutRanges } = get();
         const newRange: CutRange = {