Add explicit LLM concurrency controls

internal/core/config/config.go

@@ -36,6 +36,9 @@ type Config struct {
 	Modules                   []string
 	PrimaryLLM                LLMConfig
 	ValidationLLM             ValidationLLMConfig
+	TotalLLMConcurrency       int
+	ProposalLLMConcurrency    int
+	ValidationLLMConcurrency  *int
 	ValidationMaxPromptTokens int
 	MaxSectionTokens          int
 	MinSectionTokens          int
@@ -52,7 +55,9 @@ type LLMConfig struct {
 	BaseURL        string
 	TimeoutSeconds int
 	MaxRetries     int
-	Concurrency    int
+	// Concurrency is retained as a backward-compatible alias for
+	// TotalLLMConcurrency.
+	Concurrency int
 }
 
 type ValidationLLMConfig struct {
@@ -61,7 +66,9 @@ type ValidationLLMConfig struct {
 	BaseURL        string
 	TimeoutSeconds *int
 	MaxRetries     *int
-	Concurrency    *int
+	// Concurrency is retained as a backward-compatible alias for
+	// ValidationLLMConcurrency.
+	Concurrency *int
 }
 
 type ConfidenceThresholds struct {
@@ -91,6 +98,9 @@ func Default() Config {
 			Concurrency:    DefaultLLMConcurrency,
 		},
 		ValidationLLM:             ValidationLLMConfig{},
+		TotalLLMConcurrency:       DefaultLLMConcurrency,
+		ProposalLLMConcurrency:    DefaultLLMConcurrency,
+		ValidationLLMConcurrency:  nil,
 		ValidationMaxPromptTokens: DefaultValidationMaxPromptTokens,
 		MaxSectionTokens:          DefaultMaxSectionTokens,
 		MinSectionTokens:          DefaultMinSectionTokens,
@@ -146,9 +156,37 @@ func (c Config) EffectiveValidationLLMConfig() LLMConfig {
 	if c.ValidationLLM.MaxRetries != nil {
 		effective.MaxRetries = *c.ValidationLLM.MaxRetries
 	}
-	if c.ValidationLLM.Concurrency != nil {
-		effective.Concurrency = *c.ValidationLLM.Concurrency
-	}
+	effective.Concurrency = c.EffectiveValidationLLMConcurrency()
 
 	return effective
 }
+
+func (c Config) EffectiveValidationLLMConcurrency() int {
+	if c.ValidationLLMConcurrency != nil {
+		return *c.ValidationLLMConcurrency
+	}
+	return c.TotalLLMConcurrency
+}
+
+func (c Config) EffectiveProposalLLMConcurrency() int {
+	if c.ProposalLLMConcurrency > 0 {
+		return c.ProposalLLMConcurrency
+	}
+	return c.TotalLLMConcurrency
+}
+
+func (c *Config) syncLegacyConcurrencyAliases() {
+	if c == nil {
+		return
+	}
+	c.PrimaryLLM.Concurrency = c.TotalLLMConcurrency
+	c.ValidationLLM.Concurrency = intPtr(c.ValidationLLMConcurrency)
+}
+
+func intPtr(v *int) *int {
+	if v == nil {
+		return nil
+	}
+	x := *v
+	return &x
+}