双可执行落地：STCompiler 与 BytecodeExecutor。

- STCompiler 入口在 compiler/src/main.cpp，链 compiler+isa
- host/ 改名 executor/，BytecodeExecutor 链 vm+isa 不链 compiler
- compiler/vm 补 PUBLIC 链 isa；顶层加入 executor
- CTest：版本冒烟 2 例 + isa_roundtrip（89 断言），3/3 通过

compiler/CMakeLists.txt

@@ -6,8 +6,15 @@ project(Compiler
         VERSION 0.1
         DESCRIPTION "ST / toml 编译器")
 
-include_directories(./include)
-
 # 词法、语法、符号表、类型检查、codegen、链接都留在 compiler 一个库里
 add_library(compiler STATIC
             ./src/Lexer.cpp)
+
+target_include_directories(compiler PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_link_libraries(compiler PUBLIC isa)
+
+# 可执行入口：STCompiler <project.toml> -o <name>.stb
+add_executable(STCompiler
+               ./src/main.cpp)
+
+target_link_libraries(STCompiler PRIVATE compiler)