feat: Wired source_videos and body_sections_format into technique detai…

- "backend/routers/techniques.py"

GSD-Task: S03/T02

backend/routers/techniques.py

@@ -11,12 +11,13 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
 from database import get_session
-from models import Creator, KeyMoment, RelatedTechniqueLink, SourceVideo, TechniquePage, TechniquePageVersion
+from models import Creator, KeyMoment, RelatedTechniqueLink, SourceVideo, TechniquePage, TechniquePageVersion, TechniquePageVideo
 from schemas import (
     CreatorInfo,
     KeyMomentSummary,
     PaginatedResponse,
     RelatedLinkItem,
+    SourceVideoSummary,
     TechniquePageDetail,
     TechniquePageRead,
     TechniquePageVersionDetail,
@@ -223,6 +224,9 @@ async def get_technique(
             selectinload(TechniquePage.incoming_links).selectinload(
                 RelatedTechniqueLink.source_page
             ),
+            selectinload(TechniquePage.source_video_links).selectinload(
+                TechniquePageVideo.source_video
+            ),
         )
     )
     result = await db.execute(stmt)
@@ -295,12 +299,25 @@ async def get_technique(
     version_count_result = await db.execute(version_count_stmt)
     version_count = version_count_result.scalar() or 0
 
+    # Build source video list from association table
+    source_videos = [
+        SourceVideoSummary(
+            id=link.source_video.id,
+            filename=link.source_video.filename,
+            content_type=link.source_video.content_type.value if hasattr(link.source_video.content_type, 'value') else str(link.source_video.content_type),
+            added_at=link.added_at,
+        )
+        for link in page.source_video_links
+        if link.source_video is not None
+    ]
+
     return TechniquePageDetail(
         **base.model_dump(),
         key_moments=key_moment_items,
         creator_info=creator_info,
         related_links=related_links,
         version_count=version_count,
+        source_videos=source_videos,
     )