docs: prepare release 0.8.5

[lmaertin]

Consolidating latest PRs and some minor enhancements.

Added

• Model Aliases: Introduced MODEL_ALIASES to support devices whose PRODUCT_CODE differs from the model ID used in data keys and mappings
  • Replaces the former hardcoded workaround for PDHC1H1HAR1V1
  • New device supported: SEKO POOLDOSE pH+ORP CF Group Wi-Fi (PDPR1H1HAW102, FW 539187) — resolves to PDPR1H1HAW100 mapping
• New Device Mapping: Added model_PDPH1H1HAW100_FW539176.json for pH-only devices
  • New device supported: SEKO PoolDose pH (PDPH1H1HAW100, FW 539176)
• Extended Mapping: model_PDPR1H1HAW100_FW539187.json extended from 32 to 54 entities
  • 11 new binary sensor alarms (secondary overfeed, temperature, pH/chlorine concentration, system standby)
  • 6 new sensors with conversions (circulation pump, CL dosing mode, device config, temperature unit, delay statuses)
  • 5 new number entities (dosing off-timers, delay timers)

Fixed

• Session Consistency: All functions in RequestHandler now use the shared _get_session() method, enabling correct session hand-over from Home Assistant
• Response Parsing: Fixed double-read bug in get_access_point()