Remove CSSX style dictionary infrastructure — styling is just components

The entire parallel CSS system (StyleValue type, style dictionary,
keyword atom resolver, content-addressed class generation, runtime
CSS injection, localStorage caching) was built but never adopted —
the codebase already uses :class strings with defcomp components
for all styling. Remove ~3,000 lines of unused infrastructure.

Deleted:
- cssx.sx spec module (317 lines)
- style_dict.py (782 lines) and style_resolver.py (254 lines)
- StyleValue type, defkeyframes special form, build-keyframes platform fn
- Style dict JSON delivery (<script type="text/sx-styles">), cookies, localStorage
- css/merge-styles primitives, inject-style-value, fnv1a-hash platform interface

Simplified:
- defstyle now binds any value (string, function) — no StyleValue type needed
- render-attrs no longer special-cases :style StyleValue → class conversion
- Boot sequence skips style dict init step

Preserved:
- tw.css parsing + CSS class delivery (SX-Css headers, <style id="sx-css">)
- All component infrastructure (defcomp, caching, bundling, deps)
- defstyle as a binding form for reusable class strings

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

shared/sx/ref/bootstrap_py.py

@@ -199,11 +199,6 @@ class PyEmitter:
             "ho-every": "ho_every",
             "ho-for-each": "ho_for_each",
             "sf-defstyle": "sf_defstyle",
-            "sf-defkeyframes": "sf_defkeyframes",
-            "build-keyframes": "build_keyframes",
-            "style-value?": "is_style_value",
-            "style-value-class": "style_value_class",
-            "kf-name": "kf_name",
             "special-form?": "is_special_form",
             "ho-form?": "is_ho_form",
             "strip-prefix": "strip_prefix",
@@ -1080,7 +1075,7 @@ from typing import Any
 # =========================================================================
 
 from shared.sx.types import (
-    NIL, Symbol, Keyword, Lambda, Component, Continuation, Macro, StyleValue,
+    NIL, Symbol, Keyword, Lambda, Component, Continuation, Macro,
     HandlerDef, QueryDef, ActionDef, PageDef, _ShiftSignal,
 )
 from shared.sx.parser import SxExpr
@@ -1189,8 +1184,6 @@ def type_of(x):
         return "macro"
     if isinstance(x, _RawHTML):
         return "raw-html"
-    if isinstance(x, StyleValue):
-        return "style-value"
     if isinstance(x, Continuation):
         return "continuation"
     if isinstance(x, list):
@@ -1355,14 +1348,6 @@ def is_macro(x):
     return isinstance(x, Macro)
 
 
-def is_style_value(x):
-    return isinstance(x, StyleValue)
-
-
-def style_value_class(x):
-    return x.class_name
-
-
 def env_has(env, name):
     return name in env
 
@@ -1513,8 +1498,6 @@ def serialize(val):
     if t == "raw-html":
         escaped = escape_string(raw_html_content(val))
         return '(raw! "' + escaped + '")'
-    if t == "style-value":
-        return '"' + style_value_class(val) + '"'
     if t == "list":
         if not val:
             return "()"
@@ -1534,7 +1517,7 @@ def serialize(val):
 _SPECIAL_FORM_NAMES = frozenset([
     "if", "when", "cond", "case", "and", "or",
     "let", "let*", "lambda", "fn",
-    "define", "defcomp", "defmacro", "defstyle", "defkeyframes",
+    "define", "defcomp", "defmacro", "defstyle",
     "defhandler", "defpage", "defquery", "defaction", "defrelation",
     "begin", "do", "quote", "quasiquote",
     "->", "set!",
@@ -1696,7 +1679,7 @@ def aser_special(name, expr, env):
                 fn(item)
         return results if results else NIL
     # Definition forms — evaluate for side effects
-    if name in ("define", "defcomp", "defmacro", "defstyle", "defkeyframes",
+    if name in ("define", "defcomp", "defmacro", "defstyle",
                 "defhandler", "defpage", "defquery", "defaction", "defrelation"):
         trampoline(eval_expr(expr, env))
         return NIL