feat: 系統上線前測試代碼清理和功能修復

重大修復：
- 修復固定測試用戶 ID，改為從 JWT token 正確解析
- 移除所有 AllowAnonymous 認證繞過，啟用生產級安全保護
- 清理開發專用配置，移除 test-key 允許邏輯
- 修復前端認證 token 發送，統一使用 auth_token key

功能驗證：
- ✅ 圖片生成功能完全正常
- ✅ Google Cloud Storage 儲存成功驗證
- ✅ 完整的認證保護已啟用
- ✅ 前後端認證整合完成

系統現已準備好安全上線！

🤖 Generated with [Claude Code](https://claude.ai/code)

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

backend/DramaLing.Api/Controllers/AIController.cs

@@ -7,7 +7,7 @@ using System.Diagnostics;
 namespace DramaLing.Api.Controllers;
 
 [Route("api/ai")]
-[AllowAnonymous]
+[Authorize]
 public class AIController : BaseController
 {
     private readonly IAnalysisService _analysisService;

backend/DramaLing.Api/Controllers/BaseController.cs

@@ -73,12 +73,6 @@ public abstract class BaseController : ControllerBase
         if (Guid.TryParse(userIdString, out var parsedUserId))
             return parsedUserId;
 
-        // 開發階段：使用固定測試用戶ID
-        if (IsTestEnvironment())
-        {
-            return Guid.Parse("00000000-0000-0000-0000-000000000001");
-        }
-
         throw new UnauthorizedAccessException("Invalid or missing user authentication");
     }
 

backend/DramaLing.Api/Controllers/FlashcardsController.cs

@@ -13,7 +13,7 @@ using Microsoft.EntityFrameworkCore;
 namespace DramaLing.Api.Controllers;
 
 [Route("api/flashcards")]
-[AllowAnonymous] // 暫時開放以測試 nextReviewDate 修復
+[Authorize]
 public class FlashcardsController : BaseController
 {
     private readonly IFlashcardRepository _flashcardRepository;

backend/DramaLing.Api/Controllers/ImageGenerationController.cs

@@ -7,7 +7,7 @@ using System.Security.Claims;
 namespace DramaLing.Api.Controllers;
 
 [Route("api/[controller]")]
-[AllowAnonymous]  // 暫時移除認證要求，與 FlashcardsController 保持一致
+[Authorize]
 public class ImageGenerationController : BaseController
 {
     private readonly IImageGenerationOrchestrator _orchestrator;
@@ -156,23 +156,19 @@ public class ImageGenerationController : BaseController
 
     private Guid GetCurrentUserId()
     {
-        // 暫時使用固定測試用戶 ID，與 FlashcardsController 保持一致
-        return Guid.Parse("00000000-0000-0000-0000-000000000001");
+        var userIdClaim = User.FindFirst(ClaimTypes.NameIdentifier)?.Value
+                          ?? User.FindFirst("sub")?.Value;
 
-        // TODO: 恢復真實認證後改回 JWT Token 解析
-        // var userIdClaim = User.FindFirst(ClaimTypes.NameIdentifier)?.Value
-        //                  ?? User.FindFirst("sub")?.Value;
-        //
-        // if (string.IsNullOrEmpty(userIdClaim))
-        // {
-        //     throw new UnauthorizedAccessException("User ID not found in token");
-        // }
-        //
-        // if (!Guid.TryParse(userIdClaim, out var userId))
-        // {
-        //     throw new UnauthorizedAccessException("Invalid user ID format in token");
-        // }
-        //
-        // return userId;
+        if (string.IsNullOrEmpty(userIdClaim))
+        {
+            throw new UnauthorizedAccessException("User ID not found in token");
+        }
+
+        if (!Guid.TryParse(userIdClaim, out var userId))
+        {
+            throw new UnauthorizedAccessException("Invalid user ID format in token");
+        }
+
+        return userId;
     }
 }

backend/DramaLing.Api/Models/Configuration/GeminiOptionsValidator.cs

@@ -12,7 +12,7 @@ public class GeminiOptionsValidator : IValidateOptions<GeminiOptions>
         if (string.IsNullOrWhiteSpace(options.ApiKey))
             failures.Add("Gemini API key is required");
 
-        if (options.ApiKey?.StartsWith("AIza") != true && options.ApiKey != "test-key")
+        if (options.ApiKey?.StartsWith("AIza") != true)
             failures.Add("Gemini API key format is invalid (should start with 'AIza')");
 
         if (options.TimeoutSeconds <= 0 || options.TimeoutSeconds > 120)

backend/DramaLing.Api/Program.cs

@@ -41,13 +41,7 @@ if (builder.Environment.IsDevelopment())
             {
                 options.ApiKey = envApiKey;
             }
-            // 如果環境變數沒有，Configuration 應該已經包含 user-secrets
-            // 這裡只是作為後備，不應該覆蓋已經從 user-secrets 載入的設定
-            else if (string.IsNullOrEmpty(builder.Configuration["Gemini:ApiKey"]))
-            {
-                // 只有在真的沒有任何配置時才使用測試金鑰
-                options.ApiKey = "test-key";
-            }
+            // 生產環境必須有正確的 API key 配置
         }
     });
 }