Choreograph v0.2: TokenProxy, LINQ arrays, dogfooded registrations

[KenanMillet]

Summary

Expression system overhaul with rich token objects, LINQ-inspired array methods, and fully self-hosted function/constant registrations.

Changes (v0.1 → v0.2)

• TokenProxy — tokens in scope are rich proxy objects (token.left, token.name, token.pageid). Token parameters auto-resolve to proxies (orig.left). Extension namespaces as sub-objects
  (token.anchor.isAnchored). Eager/lazy/computed evaluation modes.
• LINQ array methods — .from(), .without(), .where(), .select(), .orderBy(), .first(), .last(), .any(), .count(), .ids() on arrays.
• Dogfooded registrations — all built-in functions and constants registered through the same registerFunction/registerConstant API extensions use.
• Namespace dot-notation — extension registrations use namespace.name not namespace_name.
• Auto-wrap — functions declaring returns: 'token'/'token[]' auto-wrap results with TokenProxy.
• Backward compat — tokenId, tokenName, pageId, flat left/top still work.

Backward Compatibility

No breaking changes. Old syntax still works alongside new token.X syntax.