P9-6: Create release notes template

**Estimated**: 1h
**Dependencies**: None

## Acceptance Criteria
- [ ] Release notes template created
- [ ] Changelog format documented
- [ ] Categories: Features, Fixes, Security
- [ ] Version numbering scheme defined
- [ ] Automated changelog from git commits
- [ ] Release notes visible in app store

## Tests
- [ ] Template usable
- [ ] Automated generation works
- [ ] Notes visible in stores