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/ext_api.go

@@ -1,6 +1,5 @@
 // Package handlers — ext_api.go
 //
-// v0.29.1 CS1: Extension API routes. Starlark packages serve custom
 // JSON endpoints via the existing Gin router. Mounted at
 // /s/:slug/api/*path with JWT auth.
 //