fix(postgresql): provision meson, ninja and winflexbison on windows

- the meson build assumed meson/ninja/win_flex/win_bison/perl on PATH,
  which only held on machines that had them installed
- add meson, ninja and winflexbison tool packages and declare them via
  tools@windows on postgresql, together with the existing strawberry-perl
- meson no longer ships a Windows MSI, so the wheel is installed offline
  into a venv: postgres re-invokes meson through find_program, which
  needs the real meson.exe launcher pip generates

config/pkg/lib/postgresql.yml

@@ -17,6 +17,11 @@ postgresql:
   depends@windows:
     - openssl
     - zlib
+  tools@windows:
+    - meson
+    - ninja
+    - winflexbison
+    - strawberry-perl
   suggests@unix:
     - icu
     - libxslt

config/pkg/tool/meson.yml

@@ -0,0 +1,11 @@
+meson:
+  type: tool
+  artifact:
+    binary:
+      windows-x86_64: { type: url, url: 'https://github.com/mesonbuild/meson/releases/download/1.11.1/meson-1.11.1-py3-none-any.whl', extract: '{pkg_root_path}/meson/meson-1.11.1-py3-none-any.whl' }
+  path@windows:
+    - '{pkg_root_path}\meson'
+  tool:
+    provides:
+      - meson.bat
+    binary-subdir: meson

config/pkg/tool/ninja.yml

@@ -0,0 +1,9 @@
+ninja:
+  type: tool
+  artifact:
+    binary:
+      windows-x86_64: { type: url, url: 'https://github.com/ninja-build/ninja/releases/download/v1.13.2/ninja-win.zip', extract: { ninja.exe: '{pkg_root_path}/bin/ninja.exe' } }
+  tool:
+    provides:
+      - ninja.exe
+    binary-subdir: bin

config/pkg/tool/winflexbison.yml

@@ -0,0 +1,12 @@
+winflexbison:
+  type: tool
+  artifact:
+    binary:
+      windows-x86_64: { type: url, url: 'https://github.com/lexxmark/winflexbison/releases/download/v2.5.25/win_flex_bison-2.5.25.zip', extract: '{pkg_root_path}/winflexbison' }
+  path@windows:
+    - '{pkg_root_path}\winflexbison'
+  tool:
+    provides:
+      - win_flex.exe
+      - win_bison.exe
+    binary-subdir: winflexbison

src/Package/Artifact/meson_win.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Package\Artifact;
+
+use StaticPHP\Attribute\Artifact\AfterBinaryExtract;
+use StaticPHP\Exception\EnvironmentException;
+use StaticPHP\Util\FileSystem;
+
+class meson_win
+{
+    /**
+     * Meson 1.11 dropped the Windows MSI, so the artifact is the wheel, installed offline
+     * into a private venv. The venv is not just packaging hygiene: pip generates a real
+     * meson.exe launcher there, and PostgreSQL needs one because its build re-invokes meson
+     * through find_program(), which rejects non-executables like the meson.pyz zipapp.
+     */
+    #[AfterBinaryExtract('meson', ['windows-x86_64'])]
+    public function afterExtract(string $target_path): void
+    {
+        $dir = dirname($target_path);
+        $venv = "{$dir}\\venv";
+
+        $python = null;
+        foreach (['python', 'py -3'] as $candidate) {
+            [$code] = cmd()->execWithResult("{$candidate} --version", false);
+            if ($code === 0) {
+                $python = $candidate;
+                break;
+            }
+        }
+        if ($python === null) {
+            throw new EnvironmentException('meson needs Python 3 on PATH. Install it from https://www.python.org or with `winget install Python.Python.3.13`.');
+        }
+
+        if (is_dir($venv)) {
+            FileSystem::removeDir($venv);
+        }
+        cmd()->exec("{$python} -m venv \"{$venv}\"")
+            ->exec("\"{$venv}\\Scripts\\python.exe\" -m pip install --no-index --no-deps \"{$target_path}\"");
+
+        FileSystem::writeFile("{$dir}\\meson.bat", "@echo off\r\n\"%~dp0venv\\Scripts\\meson.exe\" %*\r\n");
+    }
+}

src/Package/Library/postgresql.php

@@ -98,7 +98,8 @@ class postgresql extends LibraryPackage
             . ' -Dextra_lib_dirs=' . escapeshellarg($lib_dir);
 
         // Build only the three frontend static libs (not the server) — keeps it fast and avoids
-        // needing every backend dependency. meson/ninja/win_bison/win_flex/perl come from PATH.
+        // needing every backend dependency. meson/ninja/win_bison/win_flex/perl come from the
+        // tool packages declared in the package config (tools@windows).
         $targets = 'src/interfaces/libpq/libpq.a src/common/libpgcommon.a src/port/libpgport.a';
 
         cmd()->cd($src)