cleanup: remove 2,369 lines of dead code

Removed backup files and unused legacy scanner function.
All code verified as unreferenced.

aggregator-agent/internal/config/config.go

@@ -206,9 +206,9 @@ func loadFromFile(configPath string) (*Config, error) {
 // migrateConfig handles specific known migrations between config versions
 func migrateConfig(cfg *Config) {
 	// Update config schema version to latest
-	if cfg.Version != "4" {
-		fmt.Printf("[CONFIG] Migrating config schema from version %s to 4\n", cfg.Version)
-		cfg.Version = "4"
+	if cfg.Version != "5" {
+		fmt.Printf("[CONFIG] Migrating config schema from version %s to 5\n", cfg.Version)
+		cfg.Version = "5"
 	}
 
 	// Migration 1: Ensure minimum check-in interval (30 seconds)