refactor(thinking): remove legacy utilities and simplify model mapping

internal/util/thinking.go

@@ -91,106 +91,6 @@ func thinkingRangeFromRegistry(model string) (found bool, min int, max int, zero
 	return false, 0, 0, false, false
 }
 
-// GetModelThinkingLevels returns the discrete reasoning effort levels for the model.
-// Returns nil if the model has no thinking support or no levels defined.
-//
-// Deprecated: Access modelInfo.Thinking.Levels directly.
-func GetModelThinkingLevels(model string) []string {
-	if model == "" {
-		return nil
-	}
-	info := registry.GetGlobalRegistry().GetModelInfo(model)
-	if info == nil || info.Thinking == nil {
-		return nil
-	}
-	return info.Thinking.Levels
-}
-
-// ModelUsesThinkingLevels reports whether the model uses discrete reasoning
-// effort levels instead of numeric budgets.
-//
-// Deprecated: Check len(modelInfo.Thinking.Levels) > 0.
-func ModelUsesThinkingLevels(model string) bool {
-	levels := GetModelThinkingLevels(model)
-	return len(levels) > 0
-}
-
-// NormalizeReasoningEffortLevel validates and normalizes a reasoning effort
-// level for the given model. Returns false when the level is not supported.
-//
-// Deprecated: Use thinking.ValidateConfig for level validation.
-func NormalizeReasoningEffortLevel(model, effort string) (string, bool) {
-	levels := GetModelThinkingLevels(model)
-	if len(levels) == 0 {
-		return "", false
-	}
-	loweredEffort := strings.ToLower(strings.TrimSpace(effort))
-	for _, lvl := range levels {
-		if strings.ToLower(lvl) == loweredEffort {
-			return lvl, true
-		}
-	}
-	return "", false
-}
-
-// IsOpenAICompatibilityModel reports whether the model is registered as an OpenAI-compatibility model.
-// These models may not advertise Thinking metadata in the registry.
-//
-// Deprecated: Check modelInfo.Type == "openai-compatibility".
-func IsOpenAICompatibilityModel(model string) bool {
-	if model == "" {
-		return false
-	}
-	info := registry.GetGlobalRegistry().GetModelInfo(model)
-	if info == nil {
-		return false
-	}
-	return strings.EqualFold(strings.TrimSpace(info.Type), "openai-compatibility")
-}
-
-// ThinkingEffortToBudget maps a reasoning effort level to a numeric thinking budget (tokens),
-// clamping the result to the model's supported range.
-//
-// Mappings (values are normalized to model's supported range):
-//   - "none"    -> 0
-//   - "auto"    -> -1
-//   - "minimal" -> 512
-//   - "low"     -> 1024
-//   - "medium"  -> 8192
-//   - "high"    -> 24576
-//   - "xhigh"   -> 32768
-//
-// Returns false when the effort level is empty or unsupported.
-//
-// Deprecated: Use thinking.ConvertLevelToBudget instead.
-func ThinkingEffortToBudget(model, effort string) (int, bool) {
-	if effort == "" {
-		return 0, false
-	}
-	normalized, ok := NormalizeReasoningEffortLevel(model, effort)
-	if !ok {
-		normalized = strings.ToLower(strings.TrimSpace(effort))
-	}
-	switch normalized {
-	case "none":
-		return 0, true
-	case "auto":
-		return NormalizeThinkingBudget(model, -1), true
-	case "minimal":
-		return NormalizeThinkingBudget(model, 512), true
-	case "low":
-		return NormalizeThinkingBudget(model, 1024), true
-	case "medium":
-		return NormalizeThinkingBudget(model, 8192), true
-	case "high":
-		return NormalizeThinkingBudget(model, 24576), true
-	case "xhigh":
-		return NormalizeThinkingBudget(model, 32768), true
-	default:
-		return 0, false
-	}
-}
-
 // ThinkingLevelToBudget maps a Gemini thinkingLevel to a numeric thinking budget (tokens).
 //
 // Mappings:
@@ -220,44 +120,3 @@ func ThinkingLevelToBudget(level string) (int, bool) {
 		return 0, false
 	}
 }
-
-// ThinkingBudgetToEffort maps a numeric thinking budget (tokens)
-// to a reasoning effort level for level-based models.
-//
-// Mappings:
-//   - 0            -> "none" (or lowest supported level if model doesn't support "none")
-//   - -1           -> "auto"
-//   - 1..1024      -> "low"
-//   - 1025..8192   -> "medium"
-//   - 8193..24576  -> "high"
-//   - 24577..      -> highest supported level for the model (defaults to "xhigh")
-//
-// Returns false when the budget is unsupported (negative values other than -1).
-//
-// Deprecated: Use thinking.ConvertBudgetToLevel instead.
-func ThinkingBudgetToEffort(model string, budget int) (string, bool) {
-	switch {
-	case budget == -1:
-		return "auto", true
-	case budget < -1:
-		return "", false
-	case budget == 0:
-		if levels := GetModelThinkingLevels(model); len(levels) > 0 {
-			return levels[0], true
-		}
-		return "none", true
-	case budget > 0 && budget <= 1024:
-		return "low", true
-	case budget <= 8192:
-		return "medium", true
-	case budget <= 24576:
-		return "high", true
-	case budget > 24576:
-		if levels := GetModelThinkingLevels(model); len(levels) > 0 {
-			return levels[len(levels)-1], true
-		}
-		return "xhigh", true
-	default:
-		return "", false
-	}
-}