feat(gitattributes): expand candidate list and update docs

- Add full list of folders/files from issue #13 to CandidateProvider
- Add gitattributes command documentation to specialized-commands.rst
- Update README.md with gitattributes command and table entry
- Update SyncCommand docs to mention gitattributes call

Author: coisa

README.md

@@ -77,6 +77,9 @@ composer dev-tools skills
 # Merges and synchronizes .gitignore files
 composer dev-tools gitignore
 
+# Manages .gitattributes export-ignore rules for leaner package archives
+composer dev-tools gitattributes
+
 # Generates a LICENSE file from composer.json license information
 composer dev-tools license
 
@@ -105,7 +108,8 @@ automation assets.
 | `composer dev-tools dependencies` | Reports missing and unused Composer dependencies. |
 | `composer dev-tools docs` | Builds the HTML documentation site from PSR-4 code and `docs/`. |
 | `composer dev-tools skills` | Creates or repairs packaged skill links in `.agents/skills`. |
-| `composer dev-tools:sync` | Updates scripts, workflow stubs, `.editorconfig`, `.gitignore`, wiki setup, and packaged skills. |
+| `composer dev-tools gitattributes` | Manages export-ignore rules in .gitattributes. |
+| `composer dev-tools:sync` | Updates scripts, workflow stubs, `.editorconfig`, `.gitignore`, `.gitattributes`, wiki setup, and packaged skills. |
 
 ## 🔌 Integration
 

docs/running/specialized-commands.rst

@@ -177,9 +177,31 @@ Important details:
   missing.
 - it calls ``gitignore`` to merge the canonical .gitignore with the project's
   .gitignore;
+- it calls ``gitattributes`` to manage export-ignore rules in .gitattributes;
 - it calls ``skills`` so ``.agents/skills`` contains links to the packaged
   skill set.
 
+``gitattributes``
+----------------
+
+Manages .gitattributes export-ignore rules for leaner Composer package archives.
+
+.. code-block:: bash
+
+   composer dev-tools gitattributes
+
+Important details:
+
+- it adds export-ignore entries for repository-only files and directories;
+- it only adds entries for paths that actually exist in the repository;
+- it respects the ``extra.gitattributes.keep-in-export`` configuration to
+  keep specific paths in exported archives;
+- it preserves existing custom .gitattributes rules;
+- it deduplicates equivalent entries and sorts them with directories before
+  files, then alphabetically;
+- it uses CandidateProvider, ExistenceChecker, ExportIgnoreFilter, Merger,
+  Reader, and Writer components from the GitAttributes namespace.
+
 ``gitignore``
 -------------
 

src/GitAttributes/CandidateProvider.php

@@ -33,17 +33,25 @@ final class CandidateProvider implements CandidateProviderInterface
     public function folders(): array
     {
         return [
+            '/.changeset/',
+            '/.circleci/',
             '/.devcontainer/',
             '/.github/',
+            '/.gitlab/',
             '/.idea/',
+            '/.php-cs-fixer.cache/',
             '/.vscode/',
             '/benchmarks/',
             '/build/',
             '/coverage/',
+            '/docker/',
             '/docs/',
             '/examples/',
             '/fixtures/',
+            '/migrations/',
             '/scripts/',
+            '/src-dev/',
+            '/stubs/',
             '/tests/',
             '/tools/',
         ];
@@ -55,25 +63,66 @@ public function folders(): array
     public function files(): array
     {
         return [
+            '/.dockerignore',
             '/.editorconfig',
+            '/.env',
+            '/.env.dist',
+            '/.env.example',
             '/.gitattributes',
             '/.gitignore',
             '/.gitmodules',
+            '/.gitlab-ci.yml',
+            '/.php-cs-fixer.dist.php',
+            '/.php-cs-fixer.php',
+            '/.phpunit.result.cache',
+            '/.styleci.yml',
+            '/.travis.yml',
+            '/AGENTS.md',
             '/CODE_OF_CONDUCT.md',
             '/CONTRIBUTING.md',
+            '/Dockerfile',
+            '/GEMINI.md',
+            '/Governance.md',
             '/Makefile',
-            '/phpunit.xml.dist',
             '/README.md',
-            '/AGENTS.md',
-            '/GEMINI.md',
-            '/Dockerfile',
-            '/.dockerignore',
-            '/.env',
-            '/docker-compose.yml',
+            '/SECURITY.md',
+            '/SUPPORT.md',
+            '/UPGRADE.md',
+            '/UPGRADING.md',
+            '/Vagrantfile',
+            '/bitbucket-pipelines.yml',
+            '/codecov.yml',
+            '/composer-normalize.json',
+            '/composer-require-checker.json',
             '/docker-compose.override.yml',
+            '/docker-compose.yaml',
+            '/docker-compose.yml',
+            '/docker-bake.hcl',
             '/docker-stack.yml',
-            '/compose.yml',
-            '/compose.override.yml',
+            '/docker-stack.yaml',
+            '/ecs.php',
+            '/grumphp.yml',
+            '/grumphp.yml.dist',
+            '/infection.json',
+            '/infection.json.dist',
+            '/makefile',
+            '/phpbench.json',
+            '/phpbench.json.dist',
+            '/phpcs.xml',
+            '/phpcs.xml.dist',
+            '/phpmd.xml',
+            '/phpmd.xml.dist',
+            '/phpstan-baseline.neon',
+            '/phpstan-bootstrap.php',
+            '/phpstan.neon',
+            '/phpstan.neon.dist',
+            '/phpunit.xml.dist',
+            '/psalm-baseline.xml',
+            '/psalm.xml',
+            '/psalm.xml.dist',
+            '/rector.php',
+            '/renovate.json',
+            '/renovate.json5',
         ];
     }