feature/various minor ui improvements

[codebude]

• Improved dark theme contrast and improved spacing in share url list
• Switch statistics ranges to calendar-based options
• Disable telemetry in development environment
• Add medium to data hygiene missing attributes

[github-actions]

🧪 Test Results — 2f94bde

✅ Backend (pytest) — 1032 passed, 0 failed, 0 skipped (1032 total)
✅ CLI (pytest) — 54 passed, 0 failed, 0 skipped (54 total)
✅ Frontend (vitest) — 534 passed, 0 failed, 0 skipped (534 total)
✅ E2E (Playwright) — 79 passed, 0 failed, 0 skipped (79 total)

Summary: ✅ All 1699 tests passed