sdks/go: mirror Elydora-Go-SDK v2.0.1 under the /v2 module path

Rebuilt from the standalone f5341ed tree (durable managed-file
transactions, Kiro IDE adapter, hook retry with a bounded chain lock,
CLI version 2.0.1) with the Open-Source API trims re-applied: no admin
events, members, webhooks, deep health, token rotation, or agent
integration updates, and the mirror's freeze/unfreeze and registration
validation contracts kept. The root quickstart now imports the /v2 path.

Claude-Session: https://claude.ai/code/session_01QoUjdc7HGKTsgj5GhG8HvF

sdks/go/.gitignore

@@ -31,3 +31,4 @@ Thumbs.db
 .env.local
 *.pem
 *.key
+/elydora