Fix IGDB result selection: use DOM data attributes + pass igdb_id to backend

Two issues fixed:

1. Frontend closure bug: IGDB result buttons used Svelte {#each} closure
   with onclick={() => doUpload(result.name)}. When clicking the 3rd
   result, the 1st result's handler sometimes fired. Fixed by reading
   data-name from e.currentTarget.dataset instead of JS closure.

2. Backend scrape mismatch: when user selected 'Blood' from IGDB
   results, backend's autoScrape searched for 'Blood' and could match
   'Captain Blood' first (alphabetical), overwriting metadata.
   Now passes igdb_id along with title so backend uses the EXACT
   IGDB entry the user selected via applyIgdbId() instead of
   auto-searching.

src/main/java/com/dostalgia/UploadResource.java

@@ -34,7 +34,8 @@ public class UploadResource {
     @Consumes(MediaType.MULTIPART_FORM_DATA)
     public Response upload(
         @RestForm("file") FileUpload upload,
-        @RestForm("title") String title
+        @RestForm("title") String title,
+        @RestForm("igdb_id") Integer igdbId
     ) throws Exception {
         if (upload == null) {
             return Response.status(400).entity(Map.of("error", "No file provided")).build();
@@ -103,9 +104,13 @@ public class UploadResource {
             game.setReady(true);
             svc.save(game);
 
-            // Auto-populate from IGDB (non-blocking if credentials are set)
+            // Auto-populate from IGDB (use provided igdb_id or auto-search)
             if (igdb.isConfigured()) {
-                igdb.autoScrape(game);
+                if (igdbId != null) {
+                    igdb.applyIgdbId(game, igdbId);
+                } else {
+                    igdb.autoScrape(game);
+                }
                 if (game.isHasCover() || game.getYear() != null || game.getGenre() != null
                     || (game.getVideos() != null && !game.getVideos().isEmpty())
                     || (game.getScreenshots() != null && !game.getScreenshots().isEmpty())) {