Migrate to MyBatis with proper Controller→Service→Mapper layering

- Add MyBatis Spring Boot Starter with XML mappers and domain classes
- Create 9 mapper interfaces + XML: Restaurant, Video, Channel, Review,
  User, Stats, DaemonConfig, Search, Vector
- Create 10 domain classes with Lombok: Restaurant, VideoSummary,
  VideoDetail, VideoRestaurantLink, Channel, Review, UserInfo,
  DaemonConfig, SiteVisitStats, VectorSearchResult
- Create 7 new service classes: RestaurantService, VideoService,
  ChannelService, ReviewService, UserService, StatsService,
  DaemonConfigService
- Refactor all controllers to be thin (HTTP + auth only), delegating
  business logic to services
- Refactor SearchService, PipelineService, DaemonScheduler, AuthService,
  YouTubeService to use mappers/services instead of JDBC/repositories
- Add Jackson SNAKE_CASE property naming for consistent API responses
- Add ClobTypeHandler for Oracle CLOB→String in MyBatis
- Add IdGenerator utility for centralized UUID generation
- Delete old repository/ package (6 files), JdbcConfig, LowerCaseKeyAdvice
- VectorService retains JDBC for Oracle VECTOR type support

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

backend-java/src/main/java/com/tasteby/mapper/VideoMapper.java

@@ -0,0 +1,68 @@
+package com.tasteby.mapper;
+
+import com.tasteby.domain.VideoDetail;
+import com.tasteby.domain.VideoRestaurantLink;
+import com.tasteby.domain.VideoSummary;
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
+import java.util.Map;
+
+@Mapper
+public interface VideoMapper {
+
+    List<VideoSummary> findAll(@Param("status") String status);
+
+    VideoDetail findDetail(@Param("id") String id);
+
+    List<VideoRestaurantLink> findVideoRestaurants(@Param("videoId") String videoId);
+
+    void updateStatus(@Param("id") String id, @Param("status") String status);
+
+    void updateTitle(@Param("id") String id, @Param("title") String title);
+
+    void updateTranscript(@Param("id") String id, @Param("transcript") String transcript);
+
+    void deleteVectorsByVideoOnly(@Param("videoId") String videoId);
+
+    void deleteReviewsByVideoOnly(@Param("videoId") String videoId);
+
+    void deleteFavoritesByVideoOnly(@Param("videoId") String videoId);
+
+    void deleteRestaurantsByVideoOnly(@Param("videoId") String videoId);
+
+    void deleteVideoRestaurants(@Param("videoId") String videoId);
+
+    void deleteVideo(@Param("videoId") String videoId);
+
+    void deleteOneVideoRestaurant(@Param("videoId") String videoId, @Param("restaurantId") String restaurantId);
+
+    void cleanupOrphanVectors(@Param("restaurantId") String restaurantId);
+
+    void cleanupOrphanReviews(@Param("restaurantId") String restaurantId);
+
+    void cleanupOrphanFavorites(@Param("restaurantId") String restaurantId);
+
+    void cleanupOrphanRestaurant(@Param("restaurantId") String restaurantId);
+
+    void insertVideo(@Param("id") String id,
+                     @Param("channelId") String channelId,
+                     @Param("videoId") String videoId,
+                     @Param("title") String title,
+                     @Param("url") String url,
+                     @Param("publishedAt") String publishedAt);
+
+    List<String> getExistingVideoIds(@Param("channelId") String channelId);
+
+    String getLatestVideoDate(@Param("channelId") String channelId);
+
+    List<Map<String, Object>> findPendingVideos(@Param("limit") int limit);
+
+    void updateVideoFields(@Param("id") String id,
+                           @Param("status") String status,
+                           @Param("transcript") String transcript,
+                           @Param("llmResponse") String llmResponse);
+
+    List<Map<String, Object>> findVideosForBulkExtract();
+}