Delete evaluator.py shim: all imports go directly to bootstrapped sx_ref.py

EvalError moved to types.py. All 27 files updated to import eval_expr,
trampoline, call_lambda, etc. directly from shared.sx.ref.sx_ref instead
of through the evaluator.py indirection layer. 320/320 spec tests pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sx/html.py

@@ -28,7 +28,7 @@ import contextvars
 from typing import Any
 
 from .types import Component, Island, Keyword, Lambda, Macro, NIL, Symbol
-from .evaluator import _eval as _raw_eval, _call_component as _raw_call_component, _expand_macro, _trampoline
+from .ref.sx_ref import eval_expr as _raw_eval, call_component as _raw_call_component, expand_macro as _expand_macro, trampoline as _trampoline
 
 def _eval(expr, env):
     """Evaluate and unwrap thunks — all html.py _eval calls are non-tail."""