refactor(server): decouple services and improve architecture

- Introduce interfaces for all major services (JWT, PostAI, Comment, Message, Notification, QRCodeLogin, Upload, Vote, etc.) to support dependency inversion.
- Move query parameters from `internal/dto` to a new `internal/query` package to separate request payloads from data transfer objects.
- Refactor `internal/router` to use embedded `RouterDeps` for cleaner dependency management.
- Decouple handlers from repositories by injecting services instead of direct repository access, ensuring proper layering.
- Improve database initialization by moving it from `internal/model` to `internal/database`.
- Optimize message decryption by implementing a more efficient `BatchDecrypt` method in `MessageEncryptor` using a worker pool.
- Enhance error handling and security by implementing fail-fast checks for encryption key length during startup.
- Clean up unused code, including the `avatar` package and several unused DTOs.

internal/pkg/crypto/batch_decrypt_test.go

@@ -21,36 +21,6 @@ func BenchmarkEncryptDecryptSingle(b *testing.B) {
 	}
 }
 
-// BenchmarkBatchDecrypt 批量并行解密性能基准
-func BenchmarkBatchDecrypt(b *testing.B) {
-	key := "12345678901234567890123456789012"
-	_ = InitMessageEncryptor(key, 1)
-	encryptor := GetMessageEncryptor()
-
-	// 准备测试数据
-	sizes := []int{10, 50, 100, 500}
-
-	for _, size := range sizes {
-		b.Run(fmt.Sprintf("size_%d", size), func(b *testing.B) {
-			// 生成加密数据
-			ciphertexts := make([]string, size)
-			for i := 0; i < size; i++ {
-				msg := map[string]interface{}{
-					"type": "text",
-					"data": map[string]string{"content": fmt.Sprintf("消息内容 %d", i)},
-				}
-				plaintext, _ := json.Marshal(msg)
-				ciphertexts[i], _ = encryptor.Encrypt(plaintext)
-			}
-
-			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
-				_ = encryptor.BatchDecrypt(ciphertexts, 4)
-			}
-		})
-	}
-}
-
 // BenchmarkSerialDecrypt 串行解密性能基准（对比用）
 func BenchmarkSerialDecrypt(b *testing.B) {
 	key := "12345678901234567890123456789012"
@@ -81,12 +51,41 @@ func BenchmarkSerialDecrypt(b *testing.B) {
 	}
 }
 
+// BenchmarkBatchDecrypt 批量并行解密性能基准
+func BenchmarkBatchDecrypt(b *testing.B) {
+	key := "12345678901234567890123456789012"
+	_ = InitMessageEncryptor(key, 1)
+	encryptor := GetMessageEncryptor()
+
+	sizes := []int{10, 50, 100, 500}
+
+	for _, size := range sizes {
+		b.Run(fmt.Sprintf("size_%d", size), func(b *testing.B) {
+			// 生成加密数据
+			ciphertexts := make([]string, size)
+			for i := 0; i < size; i++ {
+				msg := map[string]interface{}{
+					"type": "text",
+					"data": map[string]string{"content": fmt.Sprintf("消息内容 %d", i)},
+				}
+				plaintext, _ := json.Marshal(msg)
+				ciphertexts[i], _ = encryptor.Encrypt(plaintext)
+			}
+
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				_ = encryptor.BatchDecrypt(ciphertexts, 4)
+			}
+		})
+	}
+}
+
+// TestBatchDecrypt 验证批量解密与单条解密结果一致
 func TestBatchDecrypt(t *testing.T) {
 	key := "12345678901234567890123456789012"
 	_ = InitMessageEncryptor(key, 1)
 	encryptor := GetMessageEncryptor()
 
-	// 准备测试数据
 	count := 100
 	ciphertexts := make([]string, count)
 	expectedContents := make([]string, count)
@@ -105,6 +104,10 @@ func TestBatchDecrypt(t *testing.T) {
 	// 批量解密
 	results := encryptor.BatchDecrypt(ciphertexts, 4)
 
+	if len(results) != count {
+		t.Fatalf("BatchDecrypt returned %d results, want %d", len(results), count)
+	}
+
 	// 验证结果
 	for i, result := range results {
 		if result == nil {