refactor: Introduce pre-consume quota and unify relay handlers

This commit introduces a major architectural refactoring to improve quota management, centralize logging, and streamline the relay handling logic.

Key changes:
- **Pre-consume Quota:** Implements a new mechanism to check and reserve user quota *before* making the request to the upstream provider. This ensures more accurate quota deduction and prevents users from exceeding their limits due to concurrent requests.

- **Unified Relay Handlers:** Refactors the relay logic to use generic handlers (e.g., `ChatHandler`, `ImageHandler`) instead of provider-specific implementations. This significantly reduces code duplication and simplifies adding new channels.

- **Centralized Logger:** A new dedicated `logger` package is introduced, and all system logging calls are migrated to use it, moving this responsibility out of the `common` package.

- **Code Reorganization:** DTOs are generalized (e.g., `dalle.go` -> `openai_image.go`) and utility code is moved to more appropriate packages (e.g., `common/http.go` -> `service/http.go`) for better code structure.

controller/token.go

@@ -3,6 +3,7 @@ package controller
 import (
 	"net/http"
 	"one-api/common"
+	"one-api/logger"
 	"one-api/model"
 	"strconv"
 
@@ -102,7 +103,7 @@ func AddToken(c *gin.Context) {
 			"success": false,
 			"message": "生成令牌失败",
 		})
-		common.SysError("failed to generate token key: " + err.Error())
+		logger.SysError("failed to generate token key: " + err.Error())
 		return
 	}
 	cleanToken := model.Token{