Implemented multiple campaign support via a campaign directory registry with explicit campaign IDs

internal/config/config.go

@@ -17,6 +17,7 @@ type Config struct {
 // PipelineConfig contains durable pipeline-level settings.
 type PipelineConfig struct {
 	Workspace    WorkspaceConfig    `yaml:"workspace"`
+	Campaigns    CampaignsConfig    `yaml:"campaigns"`
 	Storage      StorageConfig      `yaml:"storage"`
 	Spool        SpoolConfig        `yaml:"spool"`
 	Cache        CacheConfig        `yaml:"cache"`
@@ -31,9 +32,15 @@ type PipelineConfig struct {
 	Notification NotificationConfig `yaml:"notification"`
 }
 
+// CampaignsConfig configures the local campaign registry.
+type CampaignsConfig struct {
+	Root              string `yaml:"root"`
+	DefaultCampaignID string `yaml:"default_campaign_id"`
+}
+
 // CampaignConfig contains stable campaign-level identity and input defaults.
 type CampaignConfig struct {
-	Campaign            string               `yaml:"campaign"`
+	CampaignID          string               `yaml:"campaign_id"`
 	SessionTemplateFile string               `yaml:"session_template_file"`
 	Inputs              CampaignInputsConfig `yaml:"inputs"`
 }