feat: Added key_moment_count correlated subquery to technique list API…

- "backend/schemas.py"
- "backend/routers/techniques.py"
- "frontend/src/api/public-client.ts"
- "frontend/src/pages/Home.tsx"
- "frontend/src/App.css"

GSD-Task: S03/T01

backend/routers/techniques.py

@@ -38,34 +38,53 @@ async def list_techniques(
     db: AsyncSession = Depends(get_session),
 ) -> PaginatedResponse:
     """List technique pages with optional category/creator filtering."""
-    stmt = select(TechniquePage)
+    # Correlated subquery for key moment count (same pattern as creators.py)
+    key_moment_count_sq = (
+        select(func.count())
+        .where(KeyMoment.technique_page_id == TechniquePage.id)
+        .correlate(TechniquePage)
+        .scalar_subquery()
+    )
 
+    # Build base query with filters
+    base_stmt = select(TechniquePage.id)
     if category:
-        stmt = stmt.where(TechniquePage.topic_category == category)
-
+        base_stmt = base_stmt.where(TechniquePage.topic_category == category)
     if creator_slug:
-        # Join to Creator to filter by slug
-        stmt = stmt.join(Creator, TechniquePage.creator_id == Creator.id).where(
+        base_stmt = base_stmt.join(Creator, TechniquePage.creator_id == Creator.id).where(
             Creator.slug == creator_slug
         )
 
     # Count total before pagination
-    from sqlalchemy import func
-
-    count_stmt = select(func.count()).select_from(stmt.subquery())
+    count_stmt = select(func.count()).select_from(base_stmt.subquery())
     count_result = await db.execute(count_stmt)
     total = count_result.scalar() or 0
 
+    # Main query with subquery column
+    stmt = select(
+        TechniquePage,
+        key_moment_count_sq.label("key_moment_count"),
+    )
+    if category:
+        stmt = stmt.where(TechniquePage.topic_category == category)
+    if creator_slug:
+        stmt = stmt.join(Creator, TechniquePage.creator_id == Creator.id).where(
+            Creator.slug == creator_slug
+        )
+
     stmt = stmt.options(selectinload(TechniquePage.creator)).order_by(TechniquePage.created_at.desc()).offset(offset).limit(limit)
     result = await db.execute(stmt)
-    pages = result.scalars().all()
+    rows = result.all()
 
     items = []
-    for p in pages:
+    for row in rows:
+        p = row[0]
+        km_count = row[1] or 0
         item = TechniquePageRead.model_validate(p)
         if p.creator:
             item.creator_name = p.creator.name
             item.creator_slug = p.creator.slug
+        item.key_moment_count = km_count
         items.append(item)
 
     return PaginatedResponse(

backend/schemas.py

@@ -138,6 +138,7 @@ class TechniquePageRead(TechniquePageBase):
     creator_slug: str = ""
     source_quality: str | None = None
     view_count: int = 0
+    key_moment_count: int = 0
     created_at: datetime
     updated_at: datetime
 

frontend/src/App.css

@@ -1110,6 +1110,17 @@ a.app-footer__repo:hover {
   line-height: 1.4;
 }
 
+.recent-card__moments {
+  font-size: 0.75rem;
+  color: var(--color-text-tertiary);
+  white-space: nowrap;
+}
+
+.pill--tag {
+  font-size: 0.625rem;
+  padding: 0 0.375rem;
+}
+
 /* ── Search results page ──────────────────────────────────────────────────── */
 
 .search-results-page {

frontend/src/api/public-client.ts

@@ -102,6 +102,7 @@ export interface TechniqueListItem {
   creator_slug: string;
   source_quality: string | null;
   view_count: number;
+  key_moment_count: number;
   created_at: string;
   updated_at: string;
 }

frontend/src/pages/Home.tsx

@@ -210,6 +210,9 @@ export default function Home() {
                   <span className="badge badge--category">
                     {t.topic_category}
                   </span>
+                  {t.topic_tags && t.topic_tags.length > 0 && t.topic_tags.map(tag => (
+                    <span key={tag} className="pill pill--tag">{tag}</span>
+                  ))}
                   {t.summary && (
                     <span className="recent-card__summary">
                       {t.summary.length > 100
@@ -217,6 +220,11 @@ export default function Home() {
                         : t.summary}
                     </span>
                   )}
+                  {t.key_moment_count > 0 && (
+                    <span className="recent-card__moments">
+                      {t.key_moment_count} moment{t.key_moment_count !== 1 ? 's' : ''}
+                    </span>
+                  )}
                 </span>
               </Link>
             ))}