v0.2.5

cairn-miner v0.2.5

• Installer integrity. install.sh and install.ps1 now verify every
  downloaded binary against the release SHA256SUMS and refuse to run an
  unverified download (fail closed).
• Clean logs on driver hiccups. The expected GPU-init panic during backend
  probing no longer dumps a scary backtrace before the graceful CPU fallback;
  you get one clear WARN line instead.
• Docs: Windows SmartScreen note (unsigned binaries show "unknown publisher";
  click More info, then Run anyway) and corrected HiveOS guidance for AMD rigs
  (use the generic Linux OpenCL binary, not the CUDA package).