chore: add HF sync workflow and restore requirements.txt

- Add .github/workflows/sync-to-hf.yml to auto-sync main to HF Spaces
- Restore requirements.txt with pinned versions from pyproject.toml

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/sync-to-hf.yml

@@ -0,0 +1,23 @@
+name: Sync to Hugging Face Spaces
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          lfs: true
+
+      - name: Push to Hugging Face
+        env:
+          HF_TOKEN: ${{ secrets.HF_TOKEN }}
+        run: |
+          git remote add hf https://FJFehr:$HF_TOKEN@huggingface.co/spaces/FJFehr/virtual_keyboard
+          git push hf main --force

requirements.txt

@@ -0,0 +1,7 @@
+einops>=0.6
+einx>=0.3.0
+gradio==5.49.1
+huggingface_hub>=1.4.1
+mido>=1.3.3
+spaces>=0.47.0
+torch>=2.10.0