docs: CHANGELOG Unreleased entries for Stories v1 + Profile edit

### Summary

Document new pages/components and profile edit under `[Unreleased]`.

### Motivation / Problem

- Keep changelog accurate for upcoming 0.4.0.

### Acceptance Criteria

- Added/Changed bullets in CHANGELOG clearly describe Stories and Profile work.

### Target Release

v0.3.1

### Notes / Links

- File: `CHANGELOG.md`
- Plan: `docs/weekly-reports/week-5-frontend-plan.md`