chore: strip pre-fork version comments across 72 files

Removes standalone "// v0.X.X:" comment lines and inline trailing
version annotations. Keeps version references in config field docs
and compatibility notes where they describe requirements.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/handlers/admin_connections.go

@@ -1,6 +1,5 @@
 package handlers
 
-// v0.38.1: Extension connection handlers — admin/global scope.
 // Methods on AdminHandler, mirrors admin provider config pattern.
 
 import (