Update w/versioning requirements

🏠 Remote-Dev: homespace

Author: localden

docs/community/sdk-tiers.mdx

@@ -46,6 +46,12 @@ for any tier.
 **Critical Bug** refers to P0 issues (see [Priority labels](#priority-only-if-actionable) for
 detailed criteria).
 
+**Stable Release** is a published version explicitly marked as production-ready (e.g., version `1.0.0`
+or higher without pre-release identifiers like `-alpha`, `-beta`, or `-rc`).
+
+**Clear Versioning** means following idiomatic verisoning patterns with documented
+breaking change policies, so users can understand compatibility expectations when upgrading.
+
 ## Conformance Testing
 
 All SDKs are evaluated using [automated conformance tests](https://github.com/modelcontextprotocol/conformance) that validate protocol support against the published specifications. SDKs receive a conformance score based on test results: