Add GitHub community files

- CONTRIBUTING.md with development guidelines
- Issue templates for bugs and feature requests
- Pull request template

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

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,46 @@
+---
+name: Bug Report
+about: Report a bug or unexpected behavior
+title: ''
+labels: bug
+assignees: ''
+---
+
+## Describe the Bug
+
+A clear description of what the bug is.
+
+## Environment
+
+- **Home Assistant version:**
+- **Integration version:**
+- **Immich version:**
+
+## Steps to Reproduce
+
+1.
+2.
+3.
+
+## Expected Behavior
+
+What you expected to happen.
+
+## Actual Behavior
+
+What actually happened.
+
+## Logs
+
+<details>
+<summary>Relevant log entries</summary>
+
+```
+Paste logs here
+```
+
+</details>
+
+## Additional Context
+
+Any other context about the problem.