chore: add community health files

Add MIT LICENSE (root, backend, frontend), CONTRIBUTING.md, CODE_OF_CONDUCT.md,
SECURITY.md, GitHub issue templates (bug/feature), and PR template.

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

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,32 @@
+---
+name: Bug report
+about: Report a problem with temetro
+labels: bug
+---
+
+**Describe the bug**
+A clear description of what the bug is.
+
+**To reproduce**
+Steps to reproduce the behavior:
+1. 
+2. 
+3. 
+
+**Expected behavior**
+What you expected to happen.
+
+**Actual behavior**
+What actually happened.
+
+**Environment**
+- OS: 
+- Browser (if frontend): 
+- Node version: 
+- Are you running via Docker or local dev?
+
+**Screenshots / logs**
+If applicable, add screenshots or relevant log output.
+
+**Additional context**
+Any other context about the problem.