fix: return file_path instead of media_url in n8n search API

The media_url was constructed using MEDIA_BASE_URL which returned
404s. Now returns actual file_path from database for n8n workflow.

src/api/server.rs

@@ -199,7 +199,7 @@ struct N8nSearchHit {
     text: String,
     score: f32,
     #[serde(skip_serializing_if = "Option::is_none")]
-    media_url: Option<String>,
+    file_path: Option<String>,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -840,7 +840,6 @@ async fn n8n_search(
                 qdrant.search(&query_vector, limit).await?
             };
 
-            let media_base = crate::core::config::MEDIA_BASE_URL.as_str();
             let mut hits = Vec::new();
 
             for r in search_results {
@@ -859,11 +858,11 @@ async fn n8n_search(
                         .unwrap_or("")
                         .to_string();
 
-                    let media_url = if chunk.uuid.is_empty() {
+                    let file_path = if chunk.uuid.is_empty() {
                         None
                     } else {
                         let video = pg.get_video_by_uuid(&chunk.uuid).await.ok().flatten();
-                        video.map(|v| format!("{}/{}", media_base, v.file_name))
+                        video.map(|v| v.file_path)
                     };
 
                     hits.push(N8nSearchHit {
@@ -878,7 +877,7 @@ async fn n8n_search(
                         },
                         text,
                         score: r.score,
-                        media_url,
+                        file_path,
                     });
                 }
             }