Implement runtime parameter completion fixes

internal/usecase/runner.go

@@ -92,9 +92,13 @@ func (r *Runner) Run(ctx context.Context, req domain.RunRequest) (*domain.RunRes
 	genResp, err := r.llm.Generate(ctx, domain.GenerateRequest{
 		Prompt:           domain.RenderedPrompt{SessionID: prepared.SessionID, Messages: prepared.Messages},
 		Target:           prepared.EffectiveModelParams,
+		TargetPresence:   prepared.TargetPresence,
 		StructuredOutput: prepared.StructuredOutput,
 	})
 	if err != nil {
+		if errors.Is(err, llm.ErrInvalidRequest) {
+			return nil, fmt.Errorf("%w: %w", ErrInvalidRequest, err)
+		}
 		return nil, fmt.Errorf("%w: %w", ErrLLMGenerate, err)
 	}
 
@@ -187,7 +191,7 @@ func (r *Runner) Prepare(ctx context.Context, req domain.RunRequest) (*domain.Pr
 		return nil, fmt.Errorf("%w: %w", ErrProfileLoad, err)
 	}
 
-	effectiveModel, err := resolveExecutionTarget(execProfile, req.Execution)
+	effectiveModel, targetPresence, err := resolveExecutionTarget(execProfile, req.Execution)
 	if err != nil {
 		return nil, fmt.Errorf("%w: %w", ErrInvalidRequest, err)
 	}
@@ -233,6 +237,7 @@ func (r *Runner) Prepare(ctx context.Context, req domain.RunRequest) (*domain.Pr
 		PromptHash:           promptDefinitionHash,
 		SelectedProfileID:    selectedProfileID,
 		EffectiveModelParams: effectiveModel,
+		TargetPresence:       targetPresence,
 		OutputContract:       effectiveContract,
 		StructuredOutput:     structuredOutput,
 		InputHashes:          inputHashes,
@@ -363,8 +368,9 @@ func mergeExecutionTarget(base domain.ExecutionTarget, override domain.Execution
 	return out
 }
 
-func mergeExecutionTargetOverride(base domain.ExecutionTarget, override domain.ExecutionTargetOverride) (domain.ExecutionTarget, error) {
+func mergeExecutionTargetOverride(base domain.ExecutionTarget, override domain.ExecutionTargetOverride) (domain.ExecutionTarget, domain.ExecutionTargetPresence, error) {
 	out := base
+	var presence domain.ExecutionTargetPresence
 	if override.Endpoint != "" {
 		out.Endpoint = override.Endpoint
 	}
@@ -373,27 +379,31 @@ func mergeExecutionTargetOverride(base domain.ExecutionTarget, override domain.E
 	}
 	if override.Temperature != nil {
 		if *override.Temperature < 0 || *override.Temperature > 2 {
-			return domain.ExecutionTarget{}, errors.New("temperature must be between 0 and 2")
+			return domain.ExecutionTarget{}, domain.ExecutionTargetPresence{}, errors.New("temperature must be between 0 and 2")
 		}
 		out.Temperature = *override.Temperature
+		presence.Temperature = true
 	}
 	if override.MaxTokens != nil {
 		if *override.MaxTokens < 0 {
-			return domain.ExecutionTarget{}, errors.New("max_tokens must be greater than or equal to 0")
+			return domain.ExecutionTarget{}, domain.ExecutionTargetPresence{}, errors.New("max_tokens must be greater than or equal to 0")
 		}
 		out.MaxTokens = *override.MaxTokens
+		presence.MaxTokens = true
 	}
 	if override.TopP != nil {
 		if *override.TopP < 0 || *override.TopP > 1 {
-			return domain.ExecutionTarget{}, errors.New("top_p must be between 0 and 1")
+			return domain.ExecutionTarget{}, domain.ExecutionTargetPresence{}, errors.New("top_p must be between 0 and 1")
 		}
 		out.TopP = *override.TopP
+		presence.TopP = true
 	}
 	if override.TimeoutSeconds != nil {
 		if *override.TimeoutSeconds < 0 {
-			return domain.ExecutionTarget{}, errors.New("timeout_seconds must be greater than or equal to 0")
+			return domain.ExecutionTarget{}, domain.ExecutionTargetPresence{}, errors.New("timeout_seconds must be greater than or equal to 0")
 		}
 		out.TimeoutSeconds = *override.TimeoutSeconds
+		presence.TimeoutSeconds = true
 	}
 	if strings.TrimSpace(override.ServiceTier) != "" {
 		out.ServiceTier = override.ServiceTier
@@ -407,20 +417,21 @@ func mergeExecutionTargetOverride(base domain.ExecutionTarget, override domain.E
 	if len(override.ExtraParams) > 0 {
 		out.ExtraParams = copyExtraParams(override.ExtraParams)
 	}
-	return out, nil
+	return out, presence, nil
 }
 
-func resolveExecutionTarget(profileValue *domain.ExecutionProfile, override *domain.ExecutionTargetOverride) (domain.ExecutionTarget, error) {
+func resolveExecutionTarget(profileValue *domain.ExecutionProfile, override *domain.ExecutionTargetOverride) (domain.ExecutionTarget, domain.ExecutionTargetPresence, error) {
 	out := defaults.ExecutionTargetDefault()
 	out = mergeExecutionTarget(out, executionProfileToTarget(profileValue))
+	var presence domain.ExecutionTargetPresence
 	if override != nil {
 		var err error
-		out, err = mergeExecutionTargetOverride(out, *override)
+		out, presence, err = mergeExecutionTargetOverride(out, *override)
 		if err != nil {
-			return domain.ExecutionTarget{}, err
+			return domain.ExecutionTarget{}, domain.ExecutionTargetPresence{}, err
 		}
 	}
-	return out, nil
+	return out, presence, nil
 }
 
 func validateAPIKeyEnv(apiKeyEnv string) error {