diff --git a/.env.example b/.env.example
index 88cb57f..b7bde77 100644
--- a/.env.example
+++ b/.env.example
@@ -34,7 +34,7 @@ SESSION_PATH=/
 SESSION_DOMAIN=null
 
 BROADCAST_CONNECTION=log
-FILESYSTEM_DISK=local  # 雲端應改為 s3（local 在容器重啟後會遺失上傳檔案）
+FILESYSTEM_DISK=local  # 本機開發維持 local；雲端部署改為 s3 時需一併設定下方 AWS_* 變數（含 AWS_ENDPOINT／AWS_URL）
 QUEUE_CONNECTION=redis  # 雲端建議值；database 效能較差且不利擴容
 
 CACHE_STORE=redis
@@ -60,7 +60,9 @@ AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_DEFAULT_REGION=us-east-1
 AWS_BUCKET=
-AWS_USE_PATH_STYLE_ENDPOINT=false
+AWS_ENDPOINT=  # S3 相容服務（如 Cloudflare R2）的 endpoint URL，AWS S3 本身留空即可
+AWS_URL=  # 公開存取用的網址前綴（如 R2 公開網域），留空時 fallback 為 AWS SDK 預設組法
+AWS_USE_PATH_STYLE_ENDPOINT=false  # Cloudflare R2 需設為 true
 
 VITE_APP_NAME="${APP_NAME}"
 
diff --git a/app/Console/Commands/MigrateStorageToS3.php b/app/Console/Commands/MigrateStorageToS3.php
new file mode 100644
index 0000000..1515561
--- /dev/null
+++ b/app/Console/Commands/MigrateStorageToS3.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace App\Console\Commands;
+
+use Illuminate\Console\Command;
+use Illuminate\Support\Facades\Storage;
+use Throwable;
+
+class MigrateStorageToS3 extends Command
+{
+    protected $signature = 'storage:migrate-to-s3
+                            {--dry-run : 只列出將上傳的檔案與總數，不實際執行}';
+
+    protected $description = '將本機 storage/app/public 下既有上傳檔案搬遷至 S3 相容物件儲存（public disk 切換前的一次性遷移，不刪除本機檔案）';
+
+    public function handle(): int
+    {
+        // 直接指定 local 磁碟為來源，不透過會依 FILESYSTEM_DISK 變動的 'public' disk，
+        // 避免這支指令在 FILESYSTEM_DISK 已切成 s3 後誤把來源當成目的地。
+        $source = Storage::build([
+            'driver' => 'local',
+            'root' => storage_path('app/public'),
+        ]);
+
+        $files = $source->allFiles();
+
+        if (empty($files)) {
+            $this->info('storage/app/public 底下沒有檔案，無需遷移。');
+
+            return self::SUCCESS;
+        }
+
+        if ($this->option('dry-run')) {
+            $this->info(sprintf('[dry-run] 將上傳 %d 個檔案：', count($files)));
+
+            foreach ($files as $file) {
+                $this->line("  - {$file}");
+            }
+
+            return self::SUCCESS;
+        }
+
+        $destination = Storage::disk('s3');
+        $failed = [];
+
+        $this->info(sprintf('開始上傳 %d 個檔案至 S3...', count($files)));
+        $bar = $this->output->createProgressBar(count($files));
+
+        foreach ($files as $file) {
+            try {
+                $destination->put($file, $source->get($file));
+
+                if (! $destination->exists($file)) {
+                    $failed[] = $file;
+                }
+            } catch (Throwable $e) {
+                $failed[] = $file;
+                $this->newLine();
+                $this->warn("上傳失敗：{$file}（{$e->getMessage()}）");
+            }
+
+            $bar->advance();
+        }
+
+        $bar->finish();
+        $this->newLine(2);
+
+        $succeeded = count($files) - count($failed);
+        $this->info(sprintf('完成：%d/%d 個檔案上傳成功。', $succeeded, count($files)));
+
+        if (! empty($failed)) {
+            $this->error('以下檔案上傳失敗，本機檔案未刪除，可重新執行本指令補上傳：');
+
+            foreach ($failed as $file) {
+                $this->line("  - {$file}");
+            }
+
+            return self::FAILURE;
+        }
+
+        return self::SUCCESS;
+    }
+}
diff --git a/composer.json b/composer.json
index 6cc8900..9c98590 100644
--- a/composer.json
+++ b/composer.json
@@ -13,6 +13,7 @@
         "laravel/sanctum": "^4.1",
         "laravel/socialite": "^5.20",
         "laravel/tinker": "^2.9",
+        "league/flysystem-aws-s3-v3": "^3.35",
         "predis/predis": "^3.4",
         "sentry/sentry-laravel": "^4.25"
     },
diff --git a/composer.lock b/composer.lock
index df4b54e..0f40218 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,8 +4,159 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "d2ea97103ddb23bb4bc532f34d4a2297",
+    "content-hash": "2ecac4c7d6ab5ffb62eeb2a4c6c69cb1",
     "packages": [
+        {
+            "name": "aws/aws-crt-php",
+            "version": "v1.2.7",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/awslabs/aws-crt-php.git",
+                "reference": "d71d9906c7bb63a28295447ba12e74723bd3730e"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/awslabs/aws-crt-php/zipball/d71d9906c7bb63a28295447ba12e74723bd3730e",
+                "reference": "d71d9906c7bb63a28295447ba12e74723bd3730e",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.5"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^4.8.35||^5.6.3||^9.5",
+                "yoast/phpunit-polyfills": "^1.0"
+            },
+            "suggest": {
+                "ext-awscrt": "Make sure you install awscrt native extension to use any of the functionality."
+            },
+            "type": "library",
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "Apache-2.0"
+            ],
+            "authors": [
+                {
+                    "name": "AWS SDK Common Runtime Team",
+                    "email": "aws-sdk-common-runtime@amazon.com"
+                }
+            ],
+            "description": "AWS Common Runtime for PHP",
+            "homepage": "https://github.com/awslabs/aws-crt-php",
+            "keywords": [
+                "amazon",
+                "aws",
+                "crt",
+                "sdk"
+            ],
+            "support": {
+                "issues": "https://github.com/awslabs/aws-crt-php/issues",
+                "source": "https://github.com/awslabs/aws-crt-php/tree/v1.2.7"
+            },
+            "time": "2024-10-18T22:15:13+00:00"
+        },
+        {
+            "name": "aws/aws-sdk-php",
+            "version": "3.390.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/aws/aws-sdk-php.git",
+                "reference": "a09e95bf062e15b7343f9c1362fd45c7a0dec39b"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/aws/aws-sdk-php/zipball/a09e95bf062e15b7343f9c1362fd45c7a0dec39b",
+                "reference": "a09e95bf062e15b7343f9c1362fd45c7a0dec39b",
+                "shasum": ""
+            },
+            "require": {
+                "aws/aws-crt-php": "^1.2.3",
+                "ext-json": "*",
+                "ext-pcre": "*",
+                "ext-simplexml": "*",
+                "guzzlehttp/guzzle": "^7.8.2 || ^8.0",
+                "guzzlehttp/promises": "^2.0.3 || ^3.0",
+                "guzzlehttp/psr7": "^2.6.3 || ^3.0",
+                "mtdowling/jmespath.php": "^2.9.1",
+                "php": ">=8.1",
+                "psr/http-message": "^1.0 || ^2.0",
+                "symfony/filesystem": "^v5.4.45 || ^v6.4.3 || ^v7.1.0 || ^v8.0.0"
+            },
+            "require-dev": {
+                "andrewsville/php-token-reflection": "^1.4",
+                "aws/aws-php-sns-message-validator": "~1.0",
+                "behat/behat": "~3.0",
+                "composer/composer": "^2.7.8",
+                "dms/phpunit-arraysubset-asserts": "^v0.5.0",
+                "doctrine/cache": "~1.4",
+                "ext-dom": "*",
+                "ext-openssl": "*",
+                "ext-sockets": "*",
+                "phpunit/phpunit": "^10.0",
+                "psr/cache": "^2.0 || ^3.0",
+                "psr/simple-cache": "^2.0 || ^3.0",
+                "sebastian/comparator": "^1.2.3 || ^4.0 || ^5.0",
+                "yoast/phpunit-polyfills": "^2.0"
+            },
+            "suggest": {
+                "aws/aws-php-sns-message-validator": "To validate incoming SNS notifications",
+                "doctrine/cache": "To use the DoctrineCacheAdapter",
+                "ext-curl": "To send requests using cURL",
+                "ext-openssl": "Allows working with CloudFront private distributions and verifying received SNS messages",
+                "ext-pcntl": "To use client-side monitoring",
+                "ext-sockets": "To use client-side monitoring"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.0-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "src/functions.php"
+                ],
+                "psr-4": {
+                    "Aws\\": "src/"
+                },
+                "exclude-from-classmap": [
+                    "src/data/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "Apache-2.0"
+            ],
+            "authors": [
+                {
+                    "name": "Amazon Web Services",
+                    "homepage": "https://aws.amazon.com"
+                }
+            ],
+            "description": "AWS SDK for PHP - Use Amazon Web Services in your PHP project",
+            "homepage": "https://aws.amazon.com/sdk-for-php",
+            "keywords": [
+                "amazon",
+                "aws",
+                "cloud",
+                "dynamodb",
+                "ec2",
+                "glacier",
+                "s3",
+                "sdk"
+            ],
+            "support": {
+                "forum": "https://github.com/aws/aws-sdk-php/discussions",
+                "issues": "https://github.com/aws/aws-sdk-php/issues",
+                "source": "https://github.com/aws/aws-sdk-php/tree/3.390.2"
+            },
+            "time": "2026-07-31T18:06:07+00:00"
+        },
         {
             "name": "brick/math",
             "version": "0.12.3",
@@ -2543,6 +2694,61 @@
             },
             "time": "2024-10-08T08:58:34+00:00"
         },
+        {
+            "name": "league/flysystem-aws-s3-v3",
+            "version": "3.35.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/thephpleague/flysystem-aws-s3-v3.git",
+                "reference": "8475ef9adfc6498b85469e2abec6fe3118cd08c4"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/thephpleague/flysystem-aws-s3-v3/zipball/8475ef9adfc6498b85469e2abec6fe3118cd08c4",
+                "reference": "8475ef9adfc6498b85469e2abec6fe3118cd08c4",
+                "shasum": ""
+            },
+            "require": {
+                "aws/aws-sdk-php": "^3.371.5",
+                "league/flysystem": "^3.10.0",
+                "league/mime-type-detection": "^1.0.0",
+                "php": "^8.0.2"
+            },
+            "conflict": {
+                "guzzlehttp/guzzle": "<7.0",
+                "guzzlehttp/ringphp": "<1.1.1"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "League\\Flysystem\\AwsS3V3\\": ""
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Frank de Jonge",
+                    "email": "info@frankdejonge.nl"
+                }
+            ],
+            "description": "AWS S3 filesystem adapter for Flysystem.",
+            "keywords": [
+                "Flysystem",
+                "aws",
+                "file",
+                "files",
+                "filesystem",
+                "s3",
+                "storage"
+            ],
+            "support": {
+                "source": "https://github.com/thephpleague/flysystem-aws-s3-v3/tree/3.35.2"
+            },
+            "time": "2026-07-01T23:25:49+00:00"
+        },
         {
             "name": "league/flysystem-local",
             "version": "3.29.0",
@@ -3001,6 +3207,72 @@
             ],
             "time": "2025-03-24T10:02:05+00:00"
         },
+        {
+            "name": "mtdowling/jmespath.php",
+            "version": "2.9.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/jmespath/jmespath.php.git",
+                "reference": "2157c5e50e813ec6a96c1eed3be7f64a20fb32a8"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/jmespath/jmespath.php/zipball/2157c5e50e813ec6a96c1eed3be7f64a20fb32a8",
+                "reference": "2157c5e50e813ec6a96c1eed3be7f64a20fb32a8",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.2.5 || ^8.0",
+                "symfony/polyfill-mbstring": "^1.17"
+            },
+            "require-dev": {
+                "composer/xdebug-handler": "^3.0.3",
+                "phpunit/phpunit": "^8.5.52"
+            },
+            "bin": [
+                "bin/jp.php"
+            ],
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.9-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "src/JmesPath.php"
+                ],
+                "psr-4": {
+                    "JmesPath\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Graham Campbell",
+                    "email": "hello@gjcampbell.co.uk",
+                    "homepage": "https://github.com/GrahamCampbell"
+                },
+                {
+                    "name": "Michael Dowling",
+                    "email": "mtdowling@gmail.com",
+                    "homepage": "https://github.com/mtdowling"
+                }
+            ],
+            "description": "Declaratively specify how to extract elements from a JSON document",
+            "keywords": [
+                "json",
+                "jsonpath"
+            ],
+            "support": {
+                "issues": "https://github.com/jmespath/jmespath.php/issues",
+                "source": "https://github.com/jmespath/jmespath.php/tree/2.9.2"
+            },
+            "time": "2026-07-06T18:56:19+00:00"
+        },
         {
             "name": "nesbot/carbon",
             "version": "3.9.1",
@@ -6021,6 +6293,76 @@
             ],
             "time": "2024-09-25T14:20:29+00:00"
         },
+        {
+            "name": "symfony/filesystem",
+            "version": "v7.4.15",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/filesystem.git",
+                "reference": "ff16a16bf87fdf264638b8f6995b3515975e3c79"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/filesystem/zipball/ff16a16bf87fdf264638b8f6995b3515975e3c79",
+                "reference": "ff16a16bf87fdf264638b8f6995b3515975e3c79",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=8.2",
+                "symfony/polyfill-ctype": "~1.8",
+                "symfony/polyfill-mbstring": "~1.8"
+            },
+            "require-dev": {
+                "symfony/process": "^6.4|^7.0|^8.0"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Filesystem\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Provides basic utilities for the filesystem",
+            "homepage": "https://symfony.com",
+            "support": {
+                "source": "https://github.com/symfony/filesystem/tree/v7.4.15"
+            },
+            "funding": [
+                {
+                    "url": "https://symfony.com/sponsor",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://github.com/fabpot",
+                    "type": "github"
+                },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2026-07-22T07:36:05+00:00"
+        },
         {
             "name": "symfony/finder",
             "version": "v7.2.2",
@@ -10768,5 +11110,5 @@
         "php": "^8.2"
     },
     "platform-dev": {},
-    "plugin-api-version": "2.9.0"
+    "plugin-api-version": "2.6.0"
 }
diff --git a/config/filesystems.php b/config/filesystems.php
index 44fe9c8..39f4dbb 100644
--- a/config/filesystems.php
+++ b/config/filesystems.php
@@ -36,12 +36,22 @@ return [
             'throw' => false,
         ],
 
+        // 注意：本專案所有上傳程式碼都寫死 Storage::disk('public')，不吃 'default' disk。
+        // 因此這裡讓 'public' disk 的 driver 直接讀 FILESYSTEM_DISK，而非新增一顆獨立的
+        // 's3' disk 再改呼叫點——FILESYSTEM_DISK=local 時以下 S3 專屬欄位會被忽略。
+        // 詳見 openspec/changes/cloud-ready-s3-storage/design.md 的 D1。
         'public' => [
-            'driver' => 'local',
+            'driver' => env('FILESYSTEM_DISK', 'local'),
             'root' => storage_path('app/public'),
-            'url' => env('APP_URL').'/storage',
+            'url' => env('AWS_URL') ?: env('APP_URL').'/storage',
             'visibility' => 'public',
             'throw' => false,
+            'key' => env('AWS_ACCESS_KEY_ID'),
+            'secret' => env('AWS_SECRET_ACCESS_KEY'),
+            'region' => env('AWS_DEFAULT_REGION'),
+            'bucket' => env('AWS_BUCKET'),
+            'endpoint' => env('AWS_ENDPOINT'),
+            'use_path_style_endpoint' => env('AWS_USE_PATH_STYLE_ENDPOINT', false),
         ],
 
         's3' => [
diff --git a/openspec/changes/cloud-ready-s3-storage/tasks.md b/openspec/changes/cloud-ready-s3-storage/tasks.md
index f5d1b7e..b941f02 100644
--- a/openspec/changes/cloud-ready-s3-storage/tasks.md
+++ b/openspec/changes/cloud-ready-s3-storage/tasks.md
@@ -1,21 +1,21 @@
 ## 1. 依賴與設定 [後端]
 
-- [ ] 1.1 [後端] `composer require league/flysystem-aws-s3-v3`
-- [ ] 1.2 [後端] `config/filesystems.php`：`public` disk 改為 D1 設計（`driver` 吃 `env('FILESYSTEM_DISK', 'local')`，補上 `key`/`secret`/`region`/`bucket`/`endpoint`/`use_path_style_endpoint`），並加註解說明此專案對 `FILESYSTEM_DISK` 的特殊用法
-- [ ] 1.3 [後端] `.env.example`：`FILESYSTEM_DISK` 保留 `local` 預設，更新行內註解；補齊 `AWS_ENDPOINT`、`AWS_URL`、`AWS_USE_PATH_STYLE_ENDPOINT` 三個變數與說明
+- [x] 1.1 [後端] `composer require league/flysystem-aws-s3-v3`
+- [x] 1.2 [後端] `config/filesystems.php`：`public` disk 改為 D1 設計（`driver` 吃 `env('FILESYSTEM_DISK', 'local')`，補上 `key`/`secret`/`region`/`bucket`/`endpoint`/`use_path_style_endpoint`），並加註解說明此專案對 `FILESYSTEM_DISK` 的特殊用法
+- [x] 1.3 [後端] `.env.example`：`FILESYSTEM_DISK` 保留 `local` 預設，更新行內註解；補齊 `AWS_ENDPOINT`、`AWS_URL`、`AWS_USE_PATH_STYLE_ENDPOINT` 三個變數與說明
 
 ## 2. 遷移 Command [後端]
 
-- [ ] 2.1 [後端] 新增 `app/Console/Commands/MigrateStorageToS3.php`（`storage:migrate-to-s3` 指令），掃描 `storage/app/public/` 並上傳至 `Storage::disk('s3')`，保留相對路徑，排除 `storage:link` 符號連結
-- [ ] 2.2 [後端] 實作 `--dry-run` 參數：只列出檔案清單與總數，不執行上傳
-- [ ] 2.3 [後端] 上傳後用 `Storage::disk('s3')->exists()` 驗證，失敗檔案收集成清單並於結尾印出，command 以非 0 exit code 結束（若有失敗）
-- [ ] 2.4 [後端] 確認 command 不刪除任何本機檔案（無論成功或失敗）
+- [x] 2.1 [後端] 新增 `app/Console/Commands/MigrateStorageToS3.php`（`storage:migrate-to-s3` 指令），掃描 `storage/app/public/` 並上傳至 `Storage::disk('s3')`，保留相對路徑，排除 `storage:link` 符號連結
+- [x] 2.2 [後端] 實作 `--dry-run` 參數：只列出檔案清單與總數，不執行上傳
+- [x] 2.3 [後端] 上傳後用 `Storage::disk('s3')->exists()` 驗證，失敗檔案收集成清單並於結尾印出，command 以非 0 exit code 結束（若有失敗）
+- [x] 2.4 [後端] 確認 command 不刪除任何本機檔案（無論成功或失敗）
 
 ## 3. 測試 [後端]
 
-- [ ] 3.1 [後端] `MigrateStorageToS3` command 測試：正常上傳、`--dry-run` 不執行上傳、部分失敗時正確回報且不中斷
-- [ ] 3.2 [後端] `config/filesystems.php` 改動後，既有 `CourseImageTest`／`ProviderCertification` 相關測試在 `FILESYSTEM_DISK=local`（預設）下全數通過，確認零回歸
-- [ ] 3.3 [後端] 新增測試驗證 `FILESYSTEM_DISK=local` 與未設定時行為一致（呼叫 `Storage::disk('public')` 不需任何 AWS credentials 即可運作）
+- [x] 3.1 [後端] `MigrateStorageToS3` command 測試：正常上傳、`--dry-run` 不執行上傳、部分失敗時正確回報且不中斷
+- [x] 3.2 [後端] `config/filesystems.php` 改動後，既有 `CourseImageTest`／`ProviderCertification` 相關測試在 `FILESYSTEM_DISK=local`（預設）下全數通過，確認零回歸
+- [x] 3.3 [後端] 新增測試驗證 `FILESYSTEM_DISK=local` 與未設定時行為一致（呼叫 `Storage::disk('public')` 不需任何 AWS credentials 即可運作）
 
 ## 4. R2 環境準備 [整合測試]
 
diff --git a/tests/Feature/FilesystemPublicDiskTest.php b/tests/Feature/FilesystemPublicDiskTest.php
new file mode 100644
index 0000000..be7c1a5
--- /dev/null
+++ b/tests/Feature/FilesystemPublicDiskTest.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Support\Facades\Config;
+use Illuminate\Support\Facades\Storage;
+use Tests\TestCase;
+
+class FilesystemPublicDiskTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        @unlink(storage_path('app/public/filesystem-public-disk-test.txt'));
+
+        parent::tearDown();
+    }
+
+    public function test_public_disk_works_on_local_driver_without_aws_credentials(): void
+    {
+        Config::set('filesystems.disks.public.driver', 'local');
+        Config::set('filesystems.disks.public.key', null);
+        Config::set('filesystems.disks.public.secret', null);
+        Config::set('filesystems.disks.public.region', null);
+        Config::set('filesystems.disks.public.bucket', null);
+        Config::set('filesystems.disks.public.endpoint', null);
+        Storage::forgetDisk('public');
+
+        Storage::disk('public')->put('filesystem-public-disk-test.txt', 'ok');
+
+        $this->assertTrue(Storage::disk('public')->exists('filesystem-public-disk-test.txt'));
+
+        Storage::disk('public')->delete('filesystem-public-disk-test.txt');
+    }
+
+    public function test_public_disk_driver_follows_filesystem_disk_env(): void
+    {
+        $this->assertSame(
+            env('FILESYSTEM_DISK', 'local'),
+            config('filesystems.disks.public.driver'),
+            'public disk 的 driver 應完全跟隨 FILESYSTEM_DISK env（未設定時預設 local）'
+        );
+    }
+}
diff --git a/tests/Feature/MigrateStorageToS3Test.php b/tests/Feature/MigrateStorageToS3Test.php
new file mode 100644
index 0000000..0bb3cb2
--- /dev/null
+++ b/tests/Feature/MigrateStorageToS3Test.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Support\Facades\Storage;
+use Mockery;
+use RuntimeException;
+use Tests\TestCase;
+
+class MigrateStorageToS3Test extends TestCase
+{
+    private array $createdFiles = [];
+
+    protected function tearDown(): void
+    {
+        foreach ($this->createdFiles as $relativePath) {
+            @unlink(storage_path('app/public/'.$relativePath));
+        }
+        $this->createdFiles = [];
+
+        parent::tearDown();
+    }
+
+    private function putLocalFile(string $relativePath, string $contents = 'test-content'): void
+    {
+        $fullPath = storage_path('app/public/'.$relativePath);
+        @mkdir(dirname($fullPath), 0777, true);
+        file_put_contents($fullPath, $contents);
+        $this->createdFiles[] = $relativePath;
+    }
+
+    public function test_uploads_existing_local_files_to_s3(): void
+    {
+        Storage::fake('s3');
+        $this->putLocalFile('migrate-test/one.txt', 'file-one');
+        $this->putLocalFile('migrate-test/two.txt', 'file-two');
+
+        $this->artisan('storage:migrate-to-s3')->assertSuccessful();
+
+        Storage::disk('s3')->assertExists('migrate-test/one.txt');
+        Storage::disk('s3')->assertExists('migrate-test/two.txt');
+    }
+
+    public function test_dry_run_lists_files_without_uploading(): void
+    {
+        Storage::fake('s3');
+        $this->putLocalFile('migrate-test/dry.txt');
+
+        $this->artisan('storage:migrate-to-s3', ['--dry-run' => true])->assertSuccessful();
+
+        Storage::disk('s3')->assertMissing('migrate-test/dry.txt');
+    }
+
+    public function test_no_files_to_migrate_still_succeeds(): void
+    {
+        Storage::fake('s3');
+
+        $this->artisan('storage:migrate-to-s3')->assertSuccessful();
+    }
+
+    public function test_reports_failure_and_does_not_stop_on_partial_upload_error(): void
+    {
+        $this->putLocalFile('migrate-test/ok.txt', 'ok');
+        $this->putLocalFile('migrate-test/bad.txt', 'bad');
+
+        // storage/app/public 是共用的本機目錄，可能已存在其他測試無關的檔案（如手動測試留下的
+        // 上傳圖片），所以這裡不斷言呼叫次數，只鎖定我們自己建立的兩個檔案的行為，其餘路徑一律放行。
+        $mockDisk = Mockery::mock();
+        $mockDisk->shouldReceive('put')
+            ->with('migrate-test/bad.txt', Mockery::any())
+            ->once()
+            ->andThrow(new RuntimeException('simulated network failure'));
+        $mockDisk->shouldReceive('put')
+            ->withArgs(fn (string $path) => $path !== 'migrate-test/bad.txt')
+            ->andReturn(true);
+        $mockDisk->shouldReceive('exists')->andReturn(true);
+
+        Storage::partialMock()->shouldReceive('disk')->with('s3')->andReturn($mockDisk);
+
+        $this->artisan('storage:migrate-to-s3')->assertFailed();
+    }
+}