fix: resolve retired/preview gemini model routing and test configuration errors

internal/router/heuristic.go

@@ -26,12 +26,13 @@ type ConditionRule struct {
 
 // Conditions defines the matching parameters for a rule.
 type Conditions struct {
-	AnyOfTags           []string `json:"any_of_tags,omitempty"`
-	MaxInputTokensLt    *int     `json:"max_input_tokens_lt,omitempty"`
-	RequiresReasoning   *bool    `json:"requires_reasoning,omitempty"`
-	RequiresToolCalling *bool    `json:"requires_tool_calling,omitempty"`
-	HasMultimodalInput  *bool    `json:"has_multimodal_input,omitempty"`
-	IsDefaultFallback   *bool    `json:"is_default_fallback,omitempty"`
+	AnyOfTags             []string `json:"any_of_tags,omitempty"`
+	MaxInputTokensLt      *int     `json:"max_input_tokens_lt,omitempty"`
+	RequiresReasoning     *bool    `json:"requires_reasoning,omitempty"`
+	RequiresToolCalling   *bool    `json:"requires_tool_calling,omitempty"`
+	IsSoftwareDevelopment *bool    `json:"is_software_development,omitempty"`
+	HasMultimodalInput    *bool    `json:"has_multimodal_input,omitempty"`
+	IsDefaultFallback     *bool    `json:"is_default_fallback,omitempty"`
 }
 
 func routeHeuristic(group db.ModelGroup, targets []string, routeCtx *RouteContext) (*Decision, error) {
@@ -198,6 +199,13 @@ func matchConditions(cond Conditions, routeCtx *RouteContext) bool {
 		}
 	}
 
+	// Check software development flag
+	if cond.IsSoftwareDevelopment != nil {
+		if routeCtx.IsSoftwareDevelopment != *cond.IsSoftwareDevelopment {
+			return false
+		}
+	}
+
 	// Check multimodal flag
 	if cond.HasMultimodalInput != nil {
 		if routeCtx.HasMultimodalInput != *cond.HasMultimodalInput {