Add Apple Sign In (Sign in with Apple) provider (#301)

* Initial plan

* Add Apple Sign In provider

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

* Merge 4.x into branch: add Twitter provider and resolve conflicts

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

* Revert unrelated changes (Twitter, FeiShu, PHPStan) - keep only Apple provider

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

* Verify id_token signature against Apple JWKS, validate claims, fix ES256 DER-to-P1363, validate config

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

* Resolve conflicts: rebase Apple changes on latest 4.x (with Twitter, FeiShu, WeWork, PHPStan updates)

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

* Fix phpcs (single_quote) and phpstan (string|false type) lint errors in Apple provider

Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: overtrue <1472352+overtrue@users.noreply.github.com>
Co-authored-by: 安正超 <anzhengchao@gmail.com>

Author: Copilot

README.md

@@ -8,7 +8,7 @@ Socialite 是一个 [OAuth2](https://oauth.net/2/) 认证工具。 它的灵感
 
 [![Sponsor me](https://github.com/overtrue/overtrue/blob/master/sponsor-me-button-s.svg?raw=true)](https://github.com/sponsors/overtrue)
 
-该工具现已支持平台有：Facebook，Github，Google，Linkedin，Outlook，QQ，TAPD，支付宝，淘宝，百度，钉钉，微博，微信，抖音，飞书，Lark，豆瓣，企业微信，腾讯云，Line，Gitee，Coding，Twitter。
+该工具现已支持平台有：Apple，Facebook，Github，Google，Linkedin，Outlook，QQ，TAPD，支付宝，淘宝，百度，钉钉，微博，微信，抖音，飞书，Lark，豆瓣，企业微信，腾讯云，Line，Gitee，Coding，Twitter。
 
 如果你喜欢我的项目并想支持我，[点击这里 :heart:](https://github.com/sponsors/overtrue)
 
@@ -477,6 +477,24 @@ $config = [
 ];
 ```
 
+### [Apple](https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_rest_api)
+
+通过 Apple 登录需要在 Apple Developer 后台创建 Service ID，并配置好 Return URLs。client_secret 可以直接提供，也可以通过 `team_id`、`key_id` 和 `private_key` 自动生成（推荐）。
+
+> <https://developer.apple.com/documentation/sign_in_with_apple/generate_and_validate_tokens>
+
+```php
+$config = [
+    'apple' => [
+        'client_id'   => 'com.example.app',   // Services ID
+        'team_id'     => 'XXXXXXXXXX',         // Apple Developer Team ID
+        'key_id'      => 'XXXXXXXXXX',         // Key ID from Apple Developer
+        'private_key' => file_get_contents('/path/to/AuthKey_XXXXXXXXXX.p8'), // .p8 private key content
+        'redirect'    => 'https://example.com/auth/apple/callback',
+    ],
+];
+```
+
 ## 其他一些技巧
 
 ### Scopes
@@ -659,6 +677,7 @@ $user = $socialite->userFromToken($accessToken);
 - [Line - OAuth 2.0](https://developers.line.biz/en/docs/line-login/integrate-line-login/)
 - [Gitee - OAuth文档](https://gitee.com/api/v5/oauth_doc#/)
 - [PayPal - OAuth文档](https://developer.paypal.com/docs/log-in-with-paypal/)
+- [Apple - Sign in with Apple REST API](https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_rest_api)
 
 ## PHP 扩展包开发
 

README_EN.md

@@ -8,7 +8,7 @@ Socialite is an [OAuth2](https://oauth.net/2/)  Authentication tool. It is inspi
 
 [![Sponsor me](https://github.com/overtrue/overtrue/blob/master/sponsor-me-button-s.svg?raw=true)](https://github.com/sponsors/overtrue)
 
-This tool now supports platforms such as Facebook, GitHub, Google, Figma, LinkedIn, Outlook, QQ, Tapd, Alipay, Taobao, Baidu, DingTalk, Weibo, WeChat, Douyin, Feishu, Lark, Douban, WeWork, Tencent Cloud, Line, Gitee, Coding and Twitter.
+This tool now supports platforms such as Apple, Facebook, GitHub, Google, Figma, LinkedIn, Outlook, QQ, Tapd, Alipay, Taobao, Baidu, DingTalk, Weibo, WeChat, Douyin, Feishu, Lark, Douban, WeWork, Tencent Cloud, Line, Gitee, Coding and Twitter.
 
 如果你喜欢我的项目并想支持我，[点击这里 :heart:](https://github.com/sponsors/overtrue)
 
@@ -461,6 +461,24 @@ $config = [
 ];
 ```
 
+### [Apple](https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_rest_api)
+
+Sign in with Apple requires creating a Service ID in the Apple Developer portal. You can provide a `client_secret` directly or let it be generated automatically from `team_id`, `key_id`, and `private_key` (recommended).
+
+> https://developer.apple.com/documentation/sign_in_with_apple/generate_and_validate_tokens
+
+```php
+$config = [
+    'apple' => [
+        'client_id'   => 'com.example.app',   // Services ID
+        'team_id'     => 'XXXXXXXXXX',         // Apple Developer Team ID
+        'key_id'      => 'XXXXXXXXXX',         // Key ID from Apple Developer
+        'private_key' => file_get_contents('/path/to/AuthKey_XXXXXXXXXX.p8'), // .p8 private key content
+        'redirect'    => 'https://example.com/auth/apple/callback',
+    ],
+];
+```
+
 
 
 ## Some Skill
@@ -648,6 +666,7 @@ $user = $socialite->userFromToken($accessToken);
 - [Line - OAuth 2.0](https://developers.line.biz/en/docs/line-login/integrate-line-login/)
 - [Gitee - OAuth文档](https://gitee.com/api/v5/oauth_doc#/)
 - [PayPal - OAuth文档](https://developer.paypal.com/docs/log-in-with-paypal/)
+- [Apple - Sign in with Apple REST API](https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_rest_api)
 
 [![Sponsor me](https://github.com/overtrue/overtrue/blob/master/sponsor-me.svg?raw=true)](https://github.com/sponsors/overtrue)