refactor: consolidate createFeatureChecker to inventory package

Move the duplicated createFeatureChecker implementation to a shared
NewSliceFeatureChecker function in pkg/inventory/filters.go.

- Add inventory.NewSliceFeatureChecker() as the canonical implementation
- Remove duplicate from cmd/github-mcp-server/main.go
- Remove duplicate from internal/ghmcp/server.go

This ensures the feature checking logic is DRY and maintainable.

Author: SamMorrowDrums

cmd/github-mcp-server/main.go

@@ -234,7 +234,7 @@ func getOAuthScopes(enabledToolsets, enabledTools, enabledFeatures []string, t t
 		WithReadOnly(viper.GetBool("read-only")).
 		WithToolsets(enabledToolsets).
 		WithTools(enabledTools).
-		WithFeatureChecker(createFeatureChecker(enabledFeatures))
+		WithFeatureChecker(inventory.NewSliceFeatureChecker(enabledFeatures))
 
 	inv, err := inventoryBuilder.Build()
 	if err != nil {
@@ -272,15 +272,3 @@ func collectRequiredScopes(inv *inventory.Inventory) []string {
 
 	return scopes
 }
-
-// createFeatureChecker creates a feature flag checker from enabled features list
-func createFeatureChecker(enabledFeatures []string) inventory.FeatureFlagChecker {
-	// Build a set for O(1) lookup
-	featureSet := make(map[string]bool, len(enabledFeatures))
-	for _, f := range enabledFeatures {
-		featureSet[f] = true
-	}
-	return func(_ context.Context, flagName string) (bool, error) {
-		return featureSet[flagName], nil
-	}
-}

internal/ghmcp/server.go

@@ -224,7 +224,7 @@ func NewMCPServer(cfg MCPServerConfig) (*mcp.Server, error) {
 	ghServer.AddReceivingMiddleware(addUserAgentsMiddleware(cfg, clients.rest, clients.gqlHTTP))
 
 	// Create feature checker
-	featureChecker := createFeatureChecker(cfg.EnabledFeatures)
+	featureChecker := inventory.NewSliceFeatureChecker(cfg.EnabledFeatures)
 
 	// Create dependencies for tool handlers
 	deps := github.NewBaseDeps(
@@ -325,20 +325,6 @@ func registerDynamicTools(server *mcp.Server, inventory *inventory.Inventory, de
 	}
 }
 
-// createFeatureChecker returns a FeatureFlagChecker that checks if a flag name
-// is present in the provided list of enabled features. For the local server,
-// this is populated from the --features CLI flag.
-func createFeatureChecker(enabledFeatures []string) inventory.FeatureFlagChecker {
-	// Build a set for O(1) lookup
-	featureSet := make(map[string]bool, len(enabledFeatures))
-	for _, f := range enabledFeatures {
-		featureSet[f] = true
-	}
-	return func(_ context.Context, flagName string) (bool, error) {
-		return featureSet[flagName], nil
-	}
-}
-
 type StdioServerConfig struct {
 	// Version of the server
 	Version string

pkg/inventory/filters.go

@@ -12,6 +12,18 @@ import (
 // Returns (enabled, error). If error occurs, the caller should log and treat as false.
 type FeatureFlagChecker func(ctx context.Context, flagName string) (bool, error)
 
+// NewSliceFeatureChecker creates a FeatureFlagChecker from a slice of enabled features.
+// This is a simple implementation for CLI usage where features are specified via flags.
+func NewSliceFeatureChecker(enabledFeatures []string) FeatureFlagChecker {
+	featureSet := make(map[string]bool, len(enabledFeatures))
+	for _, f := range enabledFeatures {
+		featureSet[f] = true
+	}
+	return func(_ context.Context, flagName string) (bool, error) {
+		return featureSet[flagName], nil
+	}
+}
+
 // isToolsetEnabled checks if a toolset is enabled based on current filters.
 func (r *Inventory) isToolsetEnabled(toolsetID ToolsetID) bool {
 	// Check enabled toolsets filter