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/jimeng/image.go

@@ -5,9 +5,9 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"one-api/common"
 	"one-api/dto"
 	relaycommon "one-api/relay/common"
+	"one-api/service"
 	"one-api/types"
 
 	"github.com/gin-gonic/gin"
@@ -54,7 +54,7 @@ func jimengImageHandler(c *gin.Context, resp *http.Response, info *relaycommon.R
 	if err != nil {
 		return nil, types.NewOpenAIError(err, types.ErrorCodeReadResponseBodyFailed, http.StatusInternalServerError)
 	}
-	common.CloseResponseBodyGracefully(resp)
+	service.CloseResponseBodyGracefully(resp)
 
 	err = json.Unmarshal(responseBody, &jimengResponse)
 	if err != nil {

relay/channel/jimeng/sign.go

@@ -12,7 +12,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
-	"one-api/common"
+	"one-api/logger"
 	"sort"
 	"strings"
 	"time"
@@ -44,7 +44,7 @@ func SetPayloadHash(c *gin.Context, req any) error {
 	if err != nil {
 		return err
 	}
-	common.LogInfo(c, fmt.Sprintf("SetPayloadHash body: %s", body))
+	logger.LogInfo(c, fmt.Sprintf("SetPayloadHash body: %s", body))
 	payloadHash := sha256.Sum256(body)
 	hexPayloadHash := hex.EncodeToString(payloadHash[:])
 	c.Set(HexPayloadHashKey, hexPayloadHash)