feat(verification): 教練審核流程完整版——狀態機/證照送審/Admin 裁決/通知

實作 openspec change provider-verification-workflow（25/25 tasks）：
- is_verified 升級為 verification_status 四狀態機（unsubmitted/pending/
  approved/rejected），migration 自動轉換既有資料，API 以 accessor 保留
  is_verified 相容輸出
- 教練端：證照上傳（≤3 張、複用 CompressesImages）、送審、駁回原因
  顯示與重送（/coach/verification 新頁面）
- Admin 端：審核佇列、通過/駁回（原因必填）、撤銷 approved；移除
  toggle-verified 端點（防繞過狀態機）；裁決後 flush 課程快取
- 通知：審核通過/駁回（站內+Email，駁回含原因）
- 可見性與預約入口改判 approved（行為等價）
- 測試 +18（ProviderVerificationTest 10、AdminVerificationTest 8），
  既有 4 個測試檔 helper 遷移；Swagger 同步
- 規格同步：provider-verification 全面改寫、admin-user-management
  toggle 段落改為移除聲明

容器內全套件 173 passed / 439 assertions。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

database/migrations/2026_06_12_000001_upgrade_provider_profiles_verification_status.php

@@ -0,0 +1,39 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('provider_profiles', function (Blueprint $table) {
+            $table->string('verification_status', 20)->default('unsubmitted')->after('is_verified')
+                ->comment('教練驗證狀態：unsubmitted / pending / approved / rejected');
+            $table->text('rejection_reason')->nullable()->after('verification_status');
+        });
+
+        // 既有資料轉換：已驗證視為審核通過，未驗證回到未送審
+        DB::table('provider_profiles')->where('is_verified', true)->update(['verification_status' => 'approved']);
+        DB::table('provider_profiles')->where('is_verified', false)->update(['verification_status' => 'unsubmitted']);
+
+        Schema::table('provider_profiles', function (Blueprint $table) {
+            $table->dropColumn('is_verified');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('provider_profiles', function (Blueprint $table) {
+            $table->boolean('is_verified')->default(false);
+        });
+
+        DB::table('provider_profiles')->where('verification_status', 'approved')->update(['is_verified' => true]);
+
+        Schema::table('provider_profiles', function (Blueprint $table) {
+            $table->dropColumn(['verification_status', 'rejection_reason']);
+        });
+    }
+};

database/migrations/2026_06_12_000002_create_provider_certifications_table.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('provider_certifications', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('user_id')->constrained()->cascadeOnDelete()->comment('教練 User id');
+            $table->string('image_path')->comment('證照圖片相對路徑（public disk）');
+            $table->timestamps();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('provider_certifications');
+    }
+};