🟡 P1-4: 字体大小设置实时预览 — PreviewPlayer叠加标题/字幕预览层

- PreviewPlayer新增titleSettings/subtitleSettings props
- 手机预览区内叠加标题文字（位置/字体/大小/粗体/斜体/描边/阴影实时反映）
- 字幕预览叠加层（位置/字体/大小实时反映）
- EditingPlanner传递titleSettings/subtitleSettings到PreviewPlayer
- 新增.ep-preview-title/.ep-preview-subtitle CSS样式

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web/src/pages/editing-planner/EditingPlanner.css

@@ -601,6 +601,34 @@
   color: var(--ep-text-secondary, #9ca3af);
 }
 
+/* 标题/字幕实时预览叠加层 */
+.ep-preview-title,
+.ep-preview-subtitle {
+  position: absolute;
+  left: 4px;
+  right: 4px;
+  text-align: center;
+  color: #fff;
+  line-height: 1.3;
+  pointer-events: none;
+  z-index: 5;
+  word-break: break-all;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.ep-preview-title {
+  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.7);
+}
+
+.ep-preview-subtitle {
+  background: rgba(0, 0, 0, 0.55);
+  padding: 2px 4px;
+  border-radius: 3px;
+  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
+}
+
 /* 封面预览 */
 .ep-cover-preview {
   width: 150px;

apps/web/src/pages/editing-planner/EditingPlanner.tsx

@@ -708,6 +708,8 @@ const EditingPlanner: React.FC = () => {
             currentCoverScheme={currentCoverScheme}
             coverSchemes={COVER_SCHEMES}
             aiCoverLoading={aiCoverLoading}
+            titleSettings={titleSettings}
+            subtitleSettings={subtitleSettings}
             onClipSelect={handleClipSelect}
             onCoverSchemeChange={setCurrentCoverScheme}
             onPlayPause={() => setIsPlaying(!isPlaying)}

apps/web/src/pages/editing-planner/components/PreviewPlayer.tsx

@@ -19,6 +19,26 @@ interface CoverScheme {
   label: string;
 }
 
+interface TitleSettings {
+  aiAutoSelect: boolean;
+  title: string;
+  position: string;
+  font: string;
+  size: number;
+  bold: boolean;
+  italic: boolean;
+  stroke: boolean;
+  shadow: boolean;
+}
+
+interface SubtitleSettings {
+  enabled: boolean;
+  position: string;
+  font: string;
+  size: number;
+  animation: string;
+}
+
 interface PreviewPlayerProps {
   clips: ClipData[];
   selectedClipId: string | null;
@@ -26,6 +46,8 @@ interface PreviewPlayerProps {
   currentCoverScheme: string;
   coverSchemes: CoverScheme[];
   aiCoverLoading: boolean;
+  titleSettings?: TitleSettings;
+  subtitleSettings?: SubtitleSettings;
   onClipSelect: (clipId: string) => void;
   onCoverSchemeChange: (scheme: string) => void;
   onPlayPause: () => void;
@@ -46,6 +68,8 @@ const PreviewPlayer: React.FC<PreviewPlayerProps> = ({
   currentCoverScheme,
   coverSchemes,
   aiCoverLoading,
+  titleSettings,
+  subtitleSettings,
   onCoverSchemeChange,
   onPlayPause,
   onAiGenerateCover,
@@ -78,6 +102,46 @@ const PreviewPlayer: React.FC<PreviewPlayerProps> = ({
           ) : (
             <span className="ep-phone-empty-hint">暂无片段</span>
           )}
+
+          {/* 标题实时预览 */}
+          {titleSettings && !titleSettings.aiAutoSelect && titleSettings.title && (
+            <div
+              className="ep-preview-title"
+              style={{
+                fontSize: `${Math.min(titleSettings.size, 20)}px`,
+                fontFamily: titleSettings.font,
+                fontWeight: titleSettings.bold ? "bold" : "normal",
+                fontStyle: titleSettings.italic ? "italic" : "normal",
+                textShadow: titleSettings.shadow
+                  ? "2px 2px 4px rgba(0,0,0,0.5)"
+                  : "none",
+                WebkitTextStroke: titleSettings.stroke
+                  ? "1px rgba(0,0,0,0.6)"
+                  : "none",
+                top: titleSettings.position === "top" ? "8px" : titleSettings.position === "center" ? "50%" : "auto",
+                bottom: titleSettings.position === "bottom" ? "30px" : "auto",
+                transform: titleSettings.position === "center" ? "translateY(-50%)" : "none",
+              }}
+            >
+              {titleSettings.title}
+            </div>
+          )}
+
+          {/* 字幕实时预览 */}
+          {subtitleSettings?.enabled && (
+            <div
+              className="ep-preview-subtitle"
+              style={{
+                fontSize: `${Math.min(subtitleSettings.size, 14)}px`,
+                fontFamily: subtitleSettings.font,
+                top: subtitleSettings.position === "top" ? "8px" : subtitleSettings.position === "center" ? "50%" : "auto",
+                bottom: subtitleSettings.position === "bottom" ? "8px" : "auto",
+                transform: subtitleSettings.position === "center" ? "translateY(-50%)" : "none",
+              }}
+            >
+              字幕预览文字
+            </div>
+          )}
         </div>
       </div>