feat(php-rpc): embed the Composer PHP runtime in the executable

Plugins and scripts need the real `Composer\` classes and the packages
Composer depends on, which so far came from a checkout found through
SHIRABE_COMPOSER_PHP_DIR or a path next to the workspace. Neither exists
for a distributed binary.

The build script now archives those PHP sources into a phar the way
Compiler.php does and the executable carries it. The worker maps it with
Phar::loadPhar and reads a content-addressed sentinel back to tell a
bundle it can use from one it cannot; where its PHP cannot open the phar,
the bundle is unpacked once into the cache directory and autoloaded from
there. SHIRABE_COMPOSER_PHP_DIR still overrides both for development.

PHP locates a phar's manifest by the first __HALT_COMPILER(); token in
the file, so the executable must hold no other copy of it: phar.rs builds
the token at run time, and a linter keeps further literals out of the
sources that reach the binary.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/scripts/linters/lint b/scripts/linters/lint
index 5f59945d..e90c3e0c 100755
--- a/scripts/linters/lint
+++ b/scripts/linters/lint
@@ -11,6 +11,7 @@ use Shirabe\Lint\Linters\NoBannedUse;
 use Shirabe\Lint\Linters\NoDecorativeSectionComment;
 use Shirabe\Lint\Linters\NoExceptionDowncast;
 use Shirabe\Lint\Linters\NoFormatTrailingComma;
+use Shirabe\Lint\Linters\NoHaltCompilerLiteral;
 use Shirabe\Lint\Linters\NoModRs;
 use Shirabe\Lint\Linters\NoStdCollectionsMaps;
 use Shirabe\Lint\Linters\NoUseAsAlias;
@@ -39,6 +40,9 @@ $runner = new Runner($rootDir, [
         'crates/shirabe/src/package/loader/root_package_loader.rs',
         'crates/shirabe-spdx-licenses/src/spdx_licenses.rs',
     ]],
+    [new NoHaltCompilerLiteral(), [
+        'crates/shirabe-php-rpc/build.rs',
+    ]],
     [new NoModRs(), []],
     [new NoStdCollectionsMaps(), []],
     [new NoUseAsAlias(), []],