DeviceFramework v2.9.0

DeviceFramework v2.9.0

• Add beforeSetup(callback, expectedCustomParameterCount) as an advisory
  startup allocation hint. It reserves exact registry storage before EEPROM
  emulation allocates its buffer, so constrained sketches can avoid an
  unnecessary 8-to-16 entry expansion while retaining safe fallback growth.
• Add direct const char* parameter lookup and typed-read APIs, and make the
  existing typed String reads operate on the stored value rather than a
  temporary String copy.
• Release the temporary outer WiFiManager parameter-pointer array after its
  entries have been handed to WiFiManager, while retaining the registry-owned
  parameter objects for the portal lifetime.
• Add registry occupancy/capacity diagnostics and ESP8266 regression coverage
  for exact capacity hints, fallback growth, direct reads, and portal pointer
  ownership.