fix: use fast-forward merge for true synchronization

- Remove --no-ff flag to allow fast-forward merges
- True sync: git merge main → fast-forward (no new commits)
- Update infinite loop prevention to check github-actions bot author
- Cleaner commit history without unnecessary merge commits

Author: Seungwoo321

.github/workflows/integrate-develop.yml

@@ -13,8 +13,8 @@ jobs:
   create-or-update-pr:
     name: Create or Update PR to Staging
     runs-on: ubuntu-latest
-    # Skip if this is a sync commit from main
-    if: "!contains(github.event.head_commit.message, 'chore: sync version updates from main')"
+    # Skip if this is a sync from main (by github-actions bot)
+    if: "github.event.head_commit.author.name != 'github-actions[bot]'"
     permissions:
       contents: write
       pull-requests: write

.github/workflows/update-version.yml

@@ -142,8 +142,8 @@ jobs:
           git fetch origin develop:develop
           git checkout develop
 
-          # Merge main changes
-          git merge main --no-ff -m "chore: sync version updates from main"
+          # Merge main changes (allow fast-forward for clean sync)
+          git merge main
 
           # Push directly to develop
           git push origin develop
@@ -160,8 +160,8 @@ jobs:
           git fetch origin staging:staging
           git checkout staging
 
-          # Merge main changes
-          git merge main --no-ff -m "chore: sync version updates from main"
+          # Merge main changes (allow fast-forward for clean sync)
+          git merge main
 
           # Push directly to staging
           git push origin staging