Add GitHub templates and CI workflow

- PR template
- Issue templates (bug report, feature request)
- Hassfest validation workflow

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Home Assistant Community
+    url: https://community.home-assistant.io/
+    about: Ask questions about Home Assistant
+  - name: Emby Documentation
+    url: https://emby.media/support
+    about: Emby official documentation and support