diff --git a/.woodpecker/agent-smoke.sh b/.woodpecker/agent-smoke.sh
index 94e9258..9a37bf4 100644
--- a/.woodpecker/agent-smoke.sh
+++ b/.woodpecker/agent-smoke.sh
@@ -199,9 +199,9 @@ check_script lib/ci-debug.sh
 check_script lib/parse-deps.sh
 
 # Agent scripts — list cross-sourced files where function scope flows across files.
-# phase-handler.sh calls helpers defined by its sourcing agent (action-agent.sh).
+# phase-handler.sh defines default callback stubs; sourcing agents may override.
 check_script dev/dev-agent.sh
-check_script dev/phase-handler.sh      action/action-agent.sh lib/secret-scan.sh
+check_script dev/phase-handler.sh      lib/secret-scan.sh
 check_script dev/dev-poll.sh
 check_script dev/phase-test.sh
 check_script gardener/gardener-run.sh
@@ -215,7 +215,7 @@ check_script vault/vault-fire.sh
 check_script vault/vault-poll.sh
 check_script vault/vault-reject.sh
 check_script action/action-poll.sh
-check_script action/action-agent.sh    dev/phase-handler.sh
+check_script action/action-agent.sh
 check_script supervisor/supervisor-run.sh
 check_script supervisor/preflight.sh
 check_script predictor/predictor-run.sh
diff --git a/dev/phase-handler.sh b/dev/phase-handler.sh
index ab099d6..8f3b3b4 100644
--- a/dev/phase-handler.sh
+++ b/dev/phase-handler.sh
@@ -34,6 +34,17 @@ source "$(dirname "${BASH_SOURCE[0]}")/../lib/ci-helpers.sh"
 # shellcheck source=../lib/mirrors.sh
 source "$(dirname "${BASH_SOURCE[0]}")/../lib/mirrors.sh"
 
+# --- Default callback stubs (agents can override after sourcing) ---
+# cleanup_worktree and cleanup_labels are called during phase transitions.
+# Provide no-op defaults so phase-handler.sh is self-contained; sourcing
+# agents override these with real implementations.
+if ! declare -f cleanup_worktree >/dev/null 2>&1; then
+  cleanup_worktree() { :; }
+fi
+if ! declare -f cleanup_labels >/dev/null 2>&1; then
+  cleanup_labels() { :; }
+fi
+
 # --- Default globals (agents can override after sourcing) ---
 : "${CI_POLL_TIMEOUT:=1800}"
 : "${REVIEW_POLL_TIMEOUT:=10800}"