fix: update dev branch references to main

- Study detail "View on GitHub" link: tree/dev → tree/main
- Workflows: remove dev from branch triggers (dev branch no longer exists)

Made-with: Cursor

Author: assassin808

.github/workflows/sync-studies-index.yml

@@ -1,7 +1,7 @@
 name: Sync studies index
 on:
   push:
-    branches: [dev, main]
+    branches: [main]
     paths:
       - "studies/**"
       - "scripts/build_studies_index.py"

.github/workflows/validate-studies.yml

@@ -1,7 +1,7 @@
 name: Validate studies
 on:
   pull_request:
-    branches: [dev, main]
+    branches: [main]
     paths:
       - "studies/**"
       - "scripts/build_studies_index.py"

co_website/app/studies/[studyId]/page.tsx

@@ -70,7 +70,7 @@ export default async function StudyDetailPage({
 
             <div className="flex flex-wrap gap-4">
               <a
-                href={`https://github.com/AISmithLab/HumanStudy-Bench/tree/dev/studies/${study.study_id}`}
+                href={`https://github.com/AISmithLab/HumanStudy-Bench/tree/main/studies/${study.study_id}`}
                 target="_blank"
                 rel="noopener noreferrer"
                 className="inline-flex items-center gap-2 rounded-md bg-cyan-600 px-4 py-2 text-sm font-semibold text-white shadow-sm hover:bg-cyan-500 transition-colors"