standalone: VoxelForgeCore link-safe next to Unreal -- internals in vfcore::detail, symbol check

- The copied generator, mesher and Compat stand-ins compile inside vfcore::detail.
- CheckCoreSymbols.ps1 (run by Build.ps1) fails on any unqualified Unreal-style symbol in the
  library: 16,255 on 557f6aa, 0 now. A UE 5.7 CoreMinimal.h + VoxelForgeCore.h smoke compile passes.
- Output identical: 11 hash rows at W1/W8, routes 5642/5642, look/passage/far audits pass,
  bad-shell control fails, six captures byte-identical.
Cost, measured by me interleaved (8 workers, cold, 4 runs each, first run excluded): 0.963 s vs
0.937 s for 557f6aa, ~27 ms in shape compilation; same math, so codegen/inlining. To be found.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Standalone/Compat/Json.h

@@ -1,8 +1,18 @@
 #pragma once
 
 #include <charconv>
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
 #include <fstream>
+#include <iterator>
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <utility>
 #include <variant>
+#include <vector>
 
 namespace VFJson
 {
@@ -27,7 +37,7 @@ namespace VFJson
             return It == O.end() ? Null : It->second;
         }
         double Number(double Fallback = 0.0) const { return IsNumber() ? std::get<double>(Data) : Fallback; }
-        int64 Integer(int64 Fallback = 0) const { return IsNumber() ? static_cast<int64>(std::get<double>(Data)) : Fallback; }
+        std::int64_t Integer(std::int64_t Fallback = 0) const { return IsNumber() ? static_cast<std::int64_t>(std::get<double>(Data)) : Fallback; }
         bool Boolean(bool Fallback = false) const { return std::holds_alternative<bool>(Data) ? std::get<bool>(Data) : Fallback; }
         const std::string& String() const { static const std::string Empty; return IsString() ? std::get<std::string>(Data) : Empty; }
     };
@@ -49,23 +59,23 @@ namespace VFJson
         size_t Position = 0;
         void SkipSpace() { while (Position < Text.size() && static_cast<unsigned char>(Text[Position]) <= 0x20) ++Position; }
         bool Consume(char C) { SkipSpace(); if (Position < Text.size() && Text[Position] == C) { ++Position; return true; } return false; }
-        static void AppendUtf8(std::string& Out, uint32 Code)
+        static void AppendUtf8(std::string& Out, std::uint32_t Code)
         {
             if (Code <= 0x7f) Out.push_back(static_cast<char>(Code));
             else if (Code <= 0x7ff) { Out.push_back(static_cast<char>(0xc0 | (Code >> 6))); Out.push_back(static_cast<char>(0x80 | (Code & 0x3f))); }
             else if (Code <= 0xffff) { Out.push_back(static_cast<char>(0xe0 | (Code >> 12))); Out.push_back(static_cast<char>(0x80 | ((Code >> 6) & 0x3f))); Out.push_back(static_cast<char>(0x80 | (Code & 0x3f))); }
             else { Out.push_back(static_cast<char>(0xf0 | (Code >> 18))); Out.push_back(static_cast<char>(0x80 | ((Code >> 12) & 0x3f))); Out.push_back(static_cast<char>(0x80 | ((Code >> 6) & 0x3f))); Out.push_back(static_cast<char>(0x80 | (Code & 0x3f))); }
         }
-        bool Hex4(uint32& Out)
+        bool Hex4(std::uint32_t& Out)
         {
             if (Position + 4 > Text.size()) return false;
             Out = 0;
-            for (int32 I = 0; I < 4; ++I)
+            for (std::int32_t I = 0; I < 4; ++I)
             {
                 const char C = Text[Position++];
-                const int32 N = (C >= '0' && C <= '9') ? C - '0' : (C >= 'a' && C <= 'f') ? C - 'a' + 10 : (C >= 'A' && C <= 'F') ? C - 'A' + 10 : -1;
+                const std::int32_t N = (C >= '0' && C <= '9') ? C - '0' : (C >= 'a' && C <= 'f') ? C - 'a' + 10 : (C >= 'A' && C <= 'F') ? C - 'A' + 10 : -1;
                 if (N < 0) return false;
-                Out = (Out << 4) | static_cast<uint32>(N);
+                Out = (Out << 4) | static_cast<std::uint32_t>(N);
             }
             return true;
         }
@@ -89,11 +99,11 @@ namespace VFJson
                 case 'r': Out.push_back('\r'); break; case 't': Out.push_back('\t'); break;
                 case 'u':
                 {
-                    uint32 Code = 0; if (!Hex4(Code)) { Error = "invalid JSON unicode escape"; return false; }
+                    std::uint32_t Code = 0; if (!Hex4(Code)) { Error = "invalid JSON unicode escape"; return false; }
                     if (Code >= 0xd800 && Code <= 0xdbff)
                     {
                         if (Position + 2 > Text.size() || Text[Position++] != '\\' || Text[Position++] != 'u') { Error = "missing JSON low surrogate"; return false; }
-                        uint32 Low = 0; if (!Hex4(Low) || Low < 0xdc00 || Low > 0xdfff) { Error = "invalid JSON low surrogate"; return false; }
+                        std::uint32_t Low = 0; if (!Hex4(Low) || Low < 0xdc00 || Low > 0xdfff) { Error = "invalid JSON low surrogate"; return false; }
                         Code = 0x10000 + ((Code - 0xd800) << 10) + (Low - 0xdc00);
                     }
                     AppendUtf8(Out, Code); break;