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/go.mod

@@ -1,4 +1,4 @@
-module github.com/Elydora-Infrastructure/Elydora-Go-SDK
+module github.com/Elydora-Infrastructure/Elydora-Go-SDK/v2
 
 go 1.21.0
 
@@ -6,7 +6,6 @@ require github.com/pelletier/go-toml/v2 v2.4.3
 
 require (
 	github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a
+	golang.org/x/sys v0.30.0
 	golang.org/x/term v0.29.0
 )
-
-require golang.org/x/sys v0.30.0 // indirect