Self-hosted z3.sx translator, prove.sx prover, parser unicode, auto reader macros

- z3.sx: SX-to-SMT-LIB translator written in SX (359 lines), replaces Python translation logic
- prove.sx: SMT-LIB satisfiability checker in SX — proves all 91 primitives sat by construction
- Parser: support unicode characters (em-dash, accented letters) in symbols
- Auto-resolve reader macros: #name finds name-translate in component env, no Python registration
- Platform primitives: type-of, symbol-name, keyword-name, sx-parse registered in primitives.py
- Cond heuristic: predicates ending in ? recognized as Clojure-style tests
- Library loading: z3.sx loaded at startup with reload callbacks for hot-reload ordering
- reader_z3.py: rewritten as thin shell delegating to z3.sx
- Split monolithic .sx files: essays (22), plans (13), reactive-islands (6) into separate files

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

shared/sx/primitives.py

@@ -10,7 +10,7 @@ from __future__ import annotations
 import math
 from typing import Any, Callable
 
-from .types import Keyword, NIL
+from .types import Component, Island, Keyword, Lambda, Macro, NIL, Symbol
 
 
 # ---------------------------------------------------------------------------
@@ -494,6 +494,56 @@ def prim_dict_set_mut(d: Any, key: Any, val: Any) -> Any:
     d[key] = val
     return val
 
+
+# ---------------------------------------------------------------------------
+# Type introspection — platform primitives declared in eval.sx
+# ---------------------------------------------------------------------------
+
+@register_primitive("type-of")
+def prim_type_of(x: Any) -> str:
+    if isinstance(x, bool):
+        return "boolean"
+    if isinstance(x, (int, float)):
+        return "number"
+    if isinstance(x, str):
+        return "string"
+    if x is None or x is NIL:
+        return "nil"
+    if isinstance(x, Symbol):
+        return "symbol"
+    if isinstance(x, Keyword):
+        return "keyword"
+    if isinstance(x, list):
+        return "list"
+    if isinstance(x, dict):
+        return "dict"
+    if isinstance(x, Lambda):
+        return "lambda"
+    if isinstance(x, Component):
+        return "component"
+    if isinstance(x, Island):
+        return "island"
+    if isinstance(x, Macro):
+        return "macro"
+    return "unknown"
+
+
+@register_primitive("symbol-name")
+def prim_symbol_name(s: Any) -> str:
+    return s.name if isinstance(s, Symbol) else str(s)
+
+
+@register_primitive("keyword-name")
+def prim_keyword_name(k: Any) -> str:
+    return k.name if isinstance(k, Keyword) else str(k)
+
+
+@register_primitive("sx-parse")
+def prim_sx_parse(source: str) -> list:
+    from .parser import parse_all
+    return parse_all(source)
+
+
 @register_primitive("into")
 def prim_into(target: Any, coll: Any) -> Any:
     if isinstance(target, list):