Critical fix: revert initial sync from getheaders back to getblocks.
The headers-first change (05b1fd1) broke chain continuation — after
downloading the first 2000 blocks, fresh nodes would stall because
the getheaders path has no orphan-based continuation mechanism.
The getblocks/inv/orphan cycle is required for full chain sync.
Also adds getblocks fallback to the headers handler so if headers
are used via other paths, sync still continues.
Other changes:
- Extract REST API into separate rest.cpp/rest.h
- Add REST rate limiting and CORS support
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
sami7777