optimization: Scope access is now a Kotlin interface, compiler uses direct slot access also for closures

AGENTS.md

@@ -12,3 +12,9 @@
 - `void` is a singleton of class `Void` (syntax sugar for return type).
 - Object members are always allowed even on unknown types; non-Object members require explicit casts. Remove `inspect` from Object and use `toInspectString()` instead.
 - Do not reintroduce bytecode fallback opcodes (e.g., `GET_NAME`, `EVAL_*`, `CALL_FALLBACK`) or runtime name-resolution fallbacks; all symbol resolution must stay compile-time only.
+
+## Bytecode frame-first migration plan
+- Treat frame slots as the only storage for locals/temps by default; avoid pre-creating scope slot mappings for compiled functions.
+- Create closure references only when a capture is detected; use a direct frame+slot reference (foreign slot ref) instead of scope slots.
+- Keep Scope as a lazy reflection facade: resolve name -> slot only on demand for Kotlin interop (no eager name mapping on every call).
+- Avoid PUSH_SCOPE/POP_SCOPE in bytecode for loops/functions unless dynamic name access or Kotlin reflection is requested.