History range controls now follow the configured History retention period.
- Keep ranges beyond retention visible but disabled, with a hover explanation pointing to Settings.
- Apply the same limits to CPU/RAM/disk charts, Uptime Kuma, Service checks and default period settings.
- Clamp saved selections when retention is reduced.
- Add a 30-day range for 30-day retention, with matching API support and localized labels.
- Add automated regressions for 1-, 7- and 30-day retention settings and disabled range behavior.
Validation: full CI smoke suite, JavaScript and inline browser script syntax checks, native installer syntax checks, and production dependency audit (0 vulnerabilities). The UI was reviewed locally before publishing.