[codebude]

• Fix the progress chart freeze across a DST fall-back
• Keep day and month chart ticks aligned across DST changes
• Document the DST chart fixes in the release notes
• Add an explicit timezone choice flag to user settings
• Use the explicit timezone flag during login and OIDC sign-in
• Add a reset to automatic timezone detection on the profile page
• Document the timezone fixes in the release notes

[github-actions]

🧪 Test Results — dfe8e43

✅ Backend (pytest) — 1274 passed, 0 failed, 0 skipped (1274 total)
✅ CLI (pytest) — 54 passed, 0 failed, 0 skipped (54 total)
✅ Frontend (vitest) — 588 passed, 0 failed, 0 skipped (588 total)
✅ E2E (Playwright) — 82 passed, 0 failed, 0 skipped (82 total)

Summary: ✅ All 1998 tests passed

[codebude]

This implements fixes for #129