Add Windows builders for libaom and brotli libraries

Both libraries are listed in lib.json and used as transitive dependencies
(libaom via libavif, brotli via freetype/curl) but had no Windows builder,
causing builds to fail with "library [X] is in the lib.json list but not
supported to compile".

libaom: Uses builddir instead of build to avoid collision with the
source tree's build/cmake/ directory. Matches the Unix builder's
AOM_TARGET_CPU=generic setting for portability.

brotli: Standard CMake build with shared libs and tools disabled.

Also adds static-libs-windows entry for libaom in lib.json.

config/lib.json

@@ -355,6 +355,9 @@
         "static-libs-unix": [
             "libaom.a"
         ],
+        "static-libs-windows": [
+            "aom.lib"
+        ],
         "cpp-library": true
     },
     "libargon2": {

src/SPC/builder/windows/library/brotli.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\windows\library;
+
+use SPC\store\FileSystem;
+
+class brotli extends WindowsLibraryBase
+{
+    public const NAME = 'brotli';
+
+    protected function build(): void
+    {
+        // reset cmake
+        FileSystem::resetDir($this->source_dir . '\build');
+
+        // start build
+        cmd()->cd($this->source_dir)
+            ->execWithWrapper(
+                $this->builder->makeSimpleWrapper('cmake'),
+                '-B build ' .
+                '-A x64 ' .
+                "-DCMAKE_TOOLCHAIN_FILE={$this->builder->cmake_toolchain_file} " .
+                '-DCMAKE_BUILD_TYPE=Release ' .
+                '-DBUILD_SHARED_LIBS=OFF ' .
+                '-DBROTLI_BUILD_TOOLS=OFF ' .
+                '-DBROTLI_BUNDLED_MODE=OFF ' .
+                '-DCMAKE_INSTALL_PREFIX=' . BUILD_ROOT_PATH . ' '
+            )
+            ->execWithWrapper(
+                $this->builder->makeSimpleWrapper('cmake'),
+                "--build build --config Release --target install -j{$this->builder->concurrency}"
+            );
+    }
+}

src/SPC/builder/windows/library/libaom.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\windows\library;
+
+use SPC\store\FileSystem;
+
+class libaom extends WindowsLibraryBase
+{
+    public const NAME = 'libaom';
+
+    protected function build(): void
+    {
+        // libaom source tree contains a build/cmake/ directory with its own
+        // cmake modules, so we must use a different name for the build dir.
+        FileSystem::resetDir($this->source_dir . '\builddir');
+
+        // start build
+        cmd()->cd($this->source_dir)
+            ->execWithWrapper(
+                $this->builder->makeSimpleWrapper('cmake'),
+                '-S . -B builddir ' .
+                '-A x64 ' .
+                "-DCMAKE_TOOLCHAIN_FILE={$this->builder->cmake_toolchain_file} " .
+                '-DCMAKE_BUILD_TYPE=Release ' .
+                '-DBUILD_SHARED_LIBS=OFF ' .
+                '-DAOM_TARGET_CPU=generic ' .
+                '-DENABLE_DOCS=OFF ' .
+                '-DENABLE_EXAMPLES=OFF ' .
+                '-DENABLE_TESTDATA=OFF ' .
+                '-DENABLE_TESTS=OFF ' .
+                '-DENABLE_TOOLS=OFF ' .
+                '-DCMAKE_INSTALL_PREFIX=' . BUILD_ROOT_PATH . ' '
+            )
+            ->execWithWrapper(
+                $this->builder->makeSimpleWrapper('cmake'),
+                "--build builddir --config Release --target install -j{$this->builder->concurrency}"
+            );
+    }
+}