feat: enhance text protocol conversion and advanced custom routing (#5825)

* refactor: consolidate relay protocol converters

* refactor relayconvert text converters

* feat: refine relay converters and advanced custom routing

* refactor: enhance logging and add thought signature handling for Gemini requests

* refactor: enhance channel cache and pricing endpoint handling for advanced custom models

* feat: preserve billing usage semantics

* feat: add protocol-aware billing usage

* Delete useless files

* chore: update action versions in workflow files

* chore: update Docker action versions in workflow files

* fix: harden billing usage settlement and hot-path route matching

- estimate Gemini completion tokens locally when billable usageMetadata is
  prompt-only but output content was received (e.g. client aborts the stream
  before the final chunk), and rebuild the attached billing_usage as estimated
  so settlement does not bill zero output tokens
- guard NewClaudeMessagesBillingUsage against all-zero ClaudeUsage, matching
  the OpenAI/Gemini constructors, so a zero billing_usage cannot override a
  non-zero top-level usage during settlement
- cache compiled advanced-custom route model regexes; they run on the request
  hot path and were recompiled per request
- move the effectiveBillingUsage remap to PostTextConsumeQuota only, and
  document that calculateTextQuotaSummary expects remapped usage
- document the updatePricingLock -> channelSyncLock lock ordering that
  InitChannelCache/CacheUpdateChannel rely on, and the aux-struct pitfall in
  GeminiChatResponse.UnmarshalJSON

relay/channel/vertex/adaptor.go

@@ -1,7 +1,6 @@
 package vertex
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -16,6 +15,7 @@ import (
 	"github.com/QuantumNous/new-api/relay/channel/openai"
 	relaycommon "github.com/QuantumNous/new-api/relay/common"
 	"github.com/QuantumNous/new-api/relay/constant"
+	"github.com/QuantumNous/new-api/service"
 	"github.com/QuantumNous/new-api/setting/model_setting"
 	"github.com/QuantumNous/new-api/setting/reasoning"
 	"github.com/QuantumNous/new-api/types"
@@ -267,7 +267,7 @@ func (a *Adaptor) ConvertOpenAIRequest(c *gin.Context, info *relaycommon.RelayIn
 		}
 		if len(request.ExtraBody) > 0 {
 			var extra map[string]any
-			if err := json.Unmarshal(request.ExtraBody, &extra); err == nil {
+			if err := common.Unmarshal(request.ExtraBody, &extra); err == nil {
 				if n, ok := extra["n"].(float64); ok && n > 0 {
 					imgReq.N = lo.ToPtr(uint(n))
 				}
@@ -289,19 +289,27 @@ func (a *Adaptor) ConvertOpenAIRequest(c *gin.Context, info *relaycommon.RelayIn
 		return a.ConvertImageRequest(c, info, imgReq)
 	}
 	if a.RequestMode == RequestModeClaude {
-		claudeReq, err := claude.RequestOpenAI2ClaudeMessage(c, *request)
+		result, err := service.ConvertRequest(c, info, types.RelayFormatClaude, request)
 		if err != nil {
 			return nil, err
 		}
+		claudeReq, ok := result.Value.(*dto.ClaudeRequest)
+		if !ok {
+			return nil, fmt.Errorf("expected Anthropic Messages request, got %T", result.Value)
+		}
 		vertexClaudeReq := copyRequest(claudeReq, anthropicVersion)
 		c.Set("request_model", claudeReq.Model)
 		info.UpstreamModelName = claudeReq.Model
 		return vertexClaudeReq, nil
 	} else if a.RequestMode == RequestModeGemini {
-		geminiRequest, err := gemini.CovertOpenAI2Gemini(c, *request, info)
+		result, err := service.ConvertRequest(c, info, types.RelayFormatGemini, request)
 		if err != nil {
 			return nil, err
 		}
+		geminiRequest, ok := result.Value.(*dto.GeminiChatRequest)
+		if !ok {
+			return nil, fmt.Errorf("expected Gemini generateContent request, got %T", result.Value)
+		}
 		c.Set("request_model", request.Model)
 		return geminiRequest, nil
 	} else if a.RequestMode == RequestModeOpenSource {