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.

relay/channel/openai/relay_responses.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"one-api/common"
 	"one-api/dto"
+	"one-api/logger"
 	relaycommon "one-api/relay/common"
 	"one-api/relay/helper"
 	"one-api/service"
@@ -16,7 +17,7 @@ import (
 )
 
 func OaiResponsesHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*dto.Usage, *types.NewAPIError) {
-	defer common.CloseResponseBodyGracefully(resp)
+	defer service.CloseResponseBodyGracefully(resp)
 
 	// read response body
 	var responsesResponse dto.OpenAIResponsesResponse
@@ -33,7 +34,7 @@ func OaiResponsesHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http
 	}
 
 	// 写入新的 response body
-	common.IOCopyBytesGracefully(c, resp, responseBody)
+	service.IOCopyBytesGracefully(c, resp, responseBody)
 
 	// compute usage
 	usage := dto.Usage{}
@@ -54,7 +55,7 @@ func OaiResponsesHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http
 
 func OaiResponsesStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*dto.Usage, *types.NewAPIError) {
 	if resp == nil || resp.Body == nil {
-		common.LogError(c, "invalid response or response body")
+		logger.LogError(c, "invalid response or response body")
 		return nil, types.NewError(fmt.Errorf("invalid response"), types.ErrorCodeBadResponse)
 	}