fix(gemini): handle minimal reasoning effort budget

- Add minimal case to clampThinkingBudgetByEffort to avoid defaulting to full thinking budget

relay/channel/gemini/relay-gemini.go

@@ -98,6 +98,7 @@ func clampThinkingBudget(modelName string, budget int) int {
 // "effort": "high" - Allocates a large portion of tokens for reasoning (approximately 80% of max_tokens)
 // "effort": "medium" - Allocates a moderate portion of tokens (approximately 50% of max_tokens)
 // "effort": "low" - Allocates a smaller portion of tokens (approximately 20% of max_tokens)
+// "effort": "minimal" - Allocates a minimal portion of tokens (approximately 5% of max_tokens)
 func clampThinkingBudgetByEffort(modelName string, effort string) int {
 	isNew25Pro := isNew25ProModel(modelName)
 	is25FlashLite := is25FlashLiteModel(modelName)
@@ -118,18 +119,12 @@ func clampThinkingBudgetByEffort(modelName string, effort string) int {
 		maxBudget = maxBudget * 50 / 100
 	case "low":
 		maxBudget = maxBudget * 20 / 100
+	case "minimal":
+		maxBudget = maxBudget * 5 / 100
 	}
 	return clampThinkingBudget(modelName, maxBudget)
 }
 
-func parseThinkingLevelSuffix(modelName string) (string, string) {
-	base, level, ok := reasoning.TrimEffortSuffix(modelName)
-	if !ok {
-		return modelName, ""
-	}
-	return base, level
-}
-
 func ThinkingAdaptor(geminiRequest *dto.GeminiChatRequest, info *relaycommon.RelayInfo, oaiRequest ...dto.GeneralOpenAIRequest) {
 	if model_setting.GetGeminiSettings().ThinkingAdapterEnabled {
 		modelName := info.UpstreamModelName
@@ -186,7 +181,7 @@ func ThinkingAdaptor(geminiRequest *dto.GeminiChatRequest, info *relaycommon.Rel
 					ThinkingBudget: common.GetPointer(0),
 				}
 			}
-		} else if _, level := parseThinkingLevelSuffix(modelName); level != "" {
+		} else if _, level, ok := reasoning.TrimEffortSuffix(info.UpstreamModelName); ok && level != "" {
 			geminiRequest.GenerationConfig.ThinkingConfig = &dto.GeminiThinkingConfig{
 				IncludeThoughts: true,
 				ThinkingLevel:   level,