CI: v18 - Use merge (not rebase), reset dirty state

- git reset --hard + git clean to avoid rebase conflicts
- Use git pull (merge) instead of pull --rebase
- Verified build times on runner:
  * botserver: 2s (incremental), 42s (cold)
  * botui: 9s (incremental)

.forgejo/workflows/botserver-v2.yaml

@@ -1,6 +1,7 @@
-# HASH-BUSTER-20260418-CONTAINER-v17
-# Only build botserver (not entire workspace)
+# HASH-BUSTER-20260418-CONTAINER-v18
+# Dev machine approach: /opt/gbo/work/botserver
 # Pre-installed globally: Rust, Node.js, Python, sccache
+# NO REBASE - use merge to avoid conflicts
 name: BotServer CI/CD
 
 on:
@@ -23,7 +24,9 @@ jobs:
       run: |
         echo "=== Pull Latest ==="
         cd /opt/gbo/work/botserver
-        git pull --rebase
+        git reset --hard HEAD
+        git clean -fd
+        git pull
         # Remove .github submodule (causes auth issues)
         rm -rf .github
         grep -v "github" .gitmodules > .gitmodules.tmp || true