refactor: move getLibExtra* to Package base, add ToolPackage support to executors and builders

- Move getLibExtraCFlags/getLibExtraCxxFlags/getLibExtraLdFlags/getLibExtraLibs from LibraryPackage to Package base class so ToolPackage can also use them
- Full ToolPackage implementation: getBuildRootPath, getIncludeDir, getLibDir, getBinDir, getToolField with platform suffix support
- Update PackageBuilder to support building ToolPackage (not just LibraryPackage)
- Update PackageInstaller: support ToolPackage in download/extract/install pipeline, auto-install build-time tools, record installed versions
- Allow LibraryPackage|ToolPackage union type in all Executor classes and UnixShell::initializeEnv

src/StaticPHP/Runtime/Shell/UnixShell.php

@@ -6,6 +6,7 @@ namespace StaticPHP\Runtime\Shell;
 
 use StaticPHP\Exception\SPCInternalException;
 use StaticPHP\Package\LibraryPackage;
+use StaticPHP\Package\ToolPackage;
 use StaticPHP\Runtime\SystemTarget;
 use ZM\Logger\ConsoleColor;
 
@@ -40,9 +41,9 @@ class UnixShell extends Shell
     /**
      * Init the environment variable that common build will be used.
      *
-     * @param LibraryPackage $library Library package
+     * @param LibraryPackage|ToolPackage $library Library or tool package
      */
-    public function initializeEnv(LibraryPackage $library): UnixShell
+    public function initializeEnv(LibraryPackage|ToolPackage $library): UnixShell
     {
         $this->setEnv([
             'CFLAGS' => $library->getLibExtraCFlags(),