docs(maintainers): use canonical identity Yoni Ryabinski (@cigan1) (#11)

Align the maintainer record with the canonical public identity (Yoni
Ryabinski, GitHub @cigan1). Docs-only; no behavior change.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: cigan1

MAINTAINERS.md

@@ -1,5 +1,5 @@
 # Maintainers
 
-- @cigan1 <cigan1@gmail.com>: SDK implementation, packaging, documentation, and release automation.
+- Yoni Ryabinski ([@cigan1](https://github.com/cigan1)) <cigan1@gmail.com>: SDK implementation, packaging, documentation, and release automation.
 
 Security reports should be sent to <hi@siftfy.io>, not posted publicly.