Copy default LLM pointers when resolving agents

ResolveAgent aliased the default config's Temperature and MaxTokens
pointers into every agent that left them unset, so all resolved
agents shared one backing value. A mutation through any of those
pointers would corrupt the default and every other agent. It also
dereferenced the default unconditionally even though it can be nil.

Allocate a fresh pointer holding a copy of the default value, and
guard against a nil default so each resolved agent owns independent
state.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/probo/document_service.go

@@ -506,9 +506,9 @@ func (s DocumentService) generateChangelog(
 		"changelog_generator",
 		s.svc.llmClient,
 		agent.WithInstructions(changelogGeneratorSystemPrompt),
-		agent.WithModel(s.svc.llmModel),
+		agent.WithModel(s.svc.llmConfig.Model),
-		agent.WithTemperature(s.svc.llmTemperature),
+		agent.WithTemperature(s.svc.llmConfig.Temperature),
-		agent.WithMaxTokens(s.svc.llmMaxTokens),
+		agent.WithMaxTokens(s.svc.llmConfig.MaxTokens),
 	)
 
 	result, err := ag.Run(

pkg/probo/service.go

@@ -59,6 +59,14 @@ type ExportService interface {
 }
 
 type (
+	// LLMConfig holds the model parameters used by the agents the probo
+	// service runs.
+	LLMConfig struct {
+		Model       string
+		Temperature float64
+		MaxTokens   int
+	}
+
 	Service struct {
 		pg                                    *pg.Client
 		s3                                    *s3.Client
@@ -67,9 +75,7 @@ type (
 		baseURL                               string
 		tokenSecret                           string
 		llmClient                             *llm.Client
-		llmModel                              string
+		llmConfig                             LLMConfig
-		llmTemperature                        float64
-		llmMaxTokens                          int
 		html2pdfConverter                     *html2pdf.Converter
 		acmeService                           *certmanager.ACMEService
 		fileManager                           *filemanager.Service
@@ -129,9 +135,7 @@ func NewService(
 	baseURL string,
 	tokenSecret string,
 	llmClient *llm.Client,
-	llmModel string,
+	llmConfig LLMConfig,
-	llmTemperature float64,
-	llmMaxTokens int,
 	html2pdfConverter *html2pdf.Converter,
 	acmeService *certmanager.ACMEService,
 	fileManagerService *filemanager.Service,
@@ -157,9 +161,7 @@ func NewService(
 		baseURL:                 baseURL,
 		tokenSecret:             tokenSecret,
 		llmClient:               llmClient,
-		llmModel:                llmModel,
+		llmConfig:               llmConfig,
-		llmTemperature:          llmTemperature,
-		llmMaxTokens:            llmMaxTokens,
 		html2pdfConverter:       html2pdfConverter,
 		acmeService:             acmeService,
 		fileManager:             fileManagerService,

pkg/probod/probod.go

@@ -39,6 +39,7 @@ import (
 	"go.gearno.de/kit/pg"
 	"go.gearno.de/kit/unit"
 	"go.gearno.de/kit/worker"
+	"go.gearno.de/x/ref"
 	"go.opentelemetry.io/otel/trace"
 	"go.probo.inc/probo/packages/emails"
 	"go.probo.inc/probo/pkg/accessreview"
@@ -507,9 +508,11 @@ func (impl *Implm) Run(
 		baseURL.String(),
 		impl.cfg.Auth.Cookie.Secret,
 		proboLLMClient,
-		proboAgentCfg.ModelName,
+		probo.LLMConfig{
-		*proboAgentCfg.Temperature,
+			Model:       proboAgentCfg.ModelName,
-		*proboAgentCfg.MaxTokens,
+			Temperature: ref.UnrefOrZero(proboAgentCfg.Temperature),
+			MaxTokens:   ref.UnrefOrZero(proboAgentCfg.MaxTokens),
+		},
 		html2pdfConverter,
 		acmeService,
 		fileManagerService,
@@ -790,8 +793,8 @@ func (impl *Implm) Run(
 		evidenceDescriberLLMClient,
 		evidencedescriber.Config{
 			Model:     evidenceDescriberAgentCfg.ModelName,
-			Temp:      *evidenceDescriberAgentCfg.Temperature,
+			Temp:      ref.UnrefOrZero(evidenceDescriberAgentCfg.Temperature),
-			MaxTokens: *evidenceDescriberAgentCfg.MaxTokens,
+			MaxTokens: ref.UnrefOrZero(evidenceDescriberAgentCfg.MaxTokens),
 		},
 	)
 	evidenceDescriptionWorker := probo.NewEvidenceDescriptionWorker(

pkg/probodconfig/llm_config.go

@@ -96,12 +96,8 @@ func (c *AgentsConfig) ResolveAgent(agent LLMAgentConfig) LLMAgentConfig {
 		agent.ModelName = c.Default.ModelName
 	}
 
-	if agent.Temperature == nil {
+	if agent.MaxTokens == nil && c.Default.MaxTokens != nil {
-		agent.Temperature = c.Default.Temperature
+		agent.MaxTokens = new(*c.Default.MaxTokens)
-	}
-
-	if agent.MaxTokens == nil {
-		agent.MaxTokens = c.Default.MaxTokens
 	}
 
 	return agent