[BE-API-003] be-api: Implement playlist search endpoint

- Added GET /playlists/search route in router.go
- Handler SearchPlaylists and service method already existed
- Supports query params: q, user_id, is_public, page, limit
- Service handles pagination, access control, and search filtering
- Route added to protected playlist group

Phase: PHASE-2
Priority: P1
Progress: 13/267 (4.9%)

VEZA_COMPLETE_MVP_TODOLIST.json

@@ -1197,7 +1197,7 @@
       "completion": {
         "completed_at": "2025-12-23T00:48:15Z",
         "actual_hours": 1.0,
-        "commits": [],
+        "commits": ["624e397"],
         "files_changed": [
           "veza-backend-api/migrations/930_add_missing_foreign_keys.sql"
         ],
@@ -1258,7 +1258,17 @@
       "description": "GET /api/v1/playlists/search with query params (q, page, limit, user_id, is_public)",
       "owner": "backend",
       "estimated_hours": 4,
-      "status": "todo",
+      "status": "completed",
+      "completion": {
+        "completed_at": "2025-12-23T00:49:14Z",
+        "actual_hours": 0.5,
+        "commits": [],
+        "files_changed": [
+          "veza-backend-api/internal/api/router.go"
+        ],
+        "notes": "Added GET /playlists/search route in router.go. Handler SearchPlaylists and service method SearchPlaylists already existed and were fully implemented. Handler supports query params: q (search query), user_id (filter by user), is_public (filter by visibility), page, limit. Service handles pagination, access control (public vs private playlists), and search filtering. Route added to protected playlist group.",
+        "issues_encountered": []
+      },
       "files_involved": [],
       "implementation_steps": [
         {

veza-backend-api/internal/api/router.go

@@ -539,6 +539,7 @@ func (r *APIRouter) setupPlaylistRoutes(router *gin.RouterGroup) {
 		{
 			playlists.GET("", playlistHandler.GetPlaylists)
 			playlists.POST("", playlistHandler.CreatePlaylist)
+			playlists.GET("/search", playlistHandler.SearchPlaylists) // BE-API-003: Playlist search endpoint
 			playlists.GET("/:id", playlistHandler.GetPlaylist)
 
 			// BE-SEC-003: Apply ownership middleware for PUT/DELETE /playlists/:id