ci: add auto-assign workflow for issues and PRs (#12)

Co-authored-by: Claude Opus 4.7 (1M context) <[email protected]>

Author: DTTerastar

.github/workflows/auto-assign.yml

@@ -0,0 +1,19 @@
+name: Auto Assign
+on:
+  issues:
+    types: [opened]
+  pull_request:
+    types: [opened]
+jobs:
+  run:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+    - name: 'Auto-assign issue'
+      uses: pozil/auto-assign-issue@v1
+      with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          assignees: DTTerastar
+          numOfAssignee: 1