diff --git a/test/smoke-test.sh b/test/smoke-test.sh
index b18ec85..b377cb5 100755
--- a/test/smoke-test.sh
+++ b/test/smoke-test.sh
@@ -166,39 +166,9 @@ done
 # Check preamble uses CLAUDE_PLUGIN_ROOT
 check "preamble supports CLAUDE_PLUGIN_ROOT" "grep -q 'CLAUDE_PLUGIN_ROOT' '$IDSTACK_DIR/templates/preamble.md'"
 
-# Migration tests
-FIXTURE_DIR="$IDSTACK_DIR/test/fixtures"
-if [ -d "$FIXTURE_DIR" ] && command -v python3 &>/dev/null; then
-  # Test v1.0 → v1.4 chained migration
-  TMPDIR_MIG=$(mktemp -d)
-  cp "$FIXTURE_DIR/manifest-v1.0.json" "$TMPDIR_MIG/project.json"
-  "$IDSTACK_DIR/bin/idstack-migrate" "$TMPDIR_MIG/project.json" >/dev/null 2>&1
-  check "v1.0→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['version']=='1.4'\""
-  check "v1.0→v1.4: has preferences" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert 'preferences' in d\""
-  check "v1.0→v1.4: preserves project_name" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['project_name']=='Test Course v1.0'\""
-  rm -rf "$TMPDIR_MIG"
-
-  # Test v1.2 → v1.4 migration
-  TMPDIR_MIG=$(mktemp -d)
-  cp "$FIXTURE_DIR/manifest-v1.2.json" "$TMPDIR_MIG/project.json"
-  "$IDSTACK_DIR/bin/idstack-migrate" "$TMPDIR_MIG/project.json" >/dev/null 2>&1
-  check "v1.2→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['version']=='1.4'\""
-  check "v1.2→v1.4: has preferences" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['preferences']['verbosity']=='normal'\""
-  check "v1.2→v1.4: idempotent" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['version']=='1.4'\" && '$IDSTACK_DIR/bin/idstack-migrate' '$TMPDIR_MIG/project.json' >/dev/null 2>&1 && python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['version']=='1.4'\""
-  rm -rf "$TMPDIR_MIG"
-
-  # Test v1.3-drifted → v1.4 cleanup migration (renames red_team_audit.summary.*_count
-  # to red_team_audit.findings_summary.*, moves _import_quality_flags into
-  # import_metadata.quality_flag_details).
-  if [ -f "$FIXTURE_DIR/manifest-v1.3-drifted.json" ]; then
-    TMPDIR_MIG=$(mktemp -d)
-    cp "$FIXTURE_DIR/manifest-v1.3-drifted.json" "$TMPDIR_MIG/project.json"
-    "$IDSTACK_DIR/bin/idstack-migrate" "$TMPDIR_MIG/project.json" >/dev/null 2>&1
-    check "v1.3-drifted→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert d['version']=='1.4'\""
-    check "v1.3-drifted→v1.4: red_team summary renamed to findings_summary" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); rt=d['red_team_audit']; assert 'summary' not in rt; assert rt['findings_summary']=={'critical': 3, 'warning': 5, 'info': 2}\""
-    check "v1.3-drifted→v1.4: _import_quality_flags moved into import_metadata" "python3 -c \"import json; d=json.load(open('$TMPDIR_MIG/project.json')); assert '_import_quality_flags' not in d; details=d['import_metadata']['quality_flag_details']; assert len(details)==2 and details[0]['key']=='orphan_module_8'\""
-    rm -rf "$TMPDIR_MIG"
-  fi
+# Migration tests (delegated to unit test suite)
+if [ -x "$IDSTACK_DIR/test/test-migrate.sh" ]; then
+  check "idstack-migrate unit tests pass" "'$IDSTACK_DIR/test/test-migrate.sh'"
 fi
 
 # Template freshness check (covers all targets: claude + codex)
diff --git a/test/test-migrate.sh b/test/test-migrate.sh
new file mode 100755
index 0000000..c89eb9c
--- /dev/null
+++ b/test/test-migrate.sh
@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+# Unit tests for bin/idstack-migrate.
+# Run from the repo root (or sourced by smoke-test.sh).
+
+set -e
+
+PASS=0
+FAIL=0
+TOTAL=0
+
+REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+MIGRATE="$REPO_ROOT/bin/idstack-migrate"
+FIXTURE_DIR="$REPO_ROOT/test/fixtures"
+
+assert() {
+  TOTAL=$((TOTAL + 1))
+  if eval "$2" >/dev/null 2>&1; then
+    PASS=$((PASS + 1))
+    echo "  PASS: $1"
+  else
+    FAIL=$((FAIL + 1))
+    echo "  FAIL: $1"
+  fi
+}
+
+# Skip the suite if python3 is missing (the tool requires python3).
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "test-migrate: python3 not available, skipping"
+  exit 0
+fi
+
+if [ ! -x "$MIGRATE" ]; then
+  echo "test-migrate: $MIGRATE missing or not executable"
+  exit 1
+fi
+
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+
+echo "test-migrate"
+echo ""
+
+# --- Test: v1.0 → v1.4 chained migration ---
+cp "$FIXTURE_DIR/manifest-v1.0.json" "$WORK/project.json"
+"$MIGRATE" "$WORK/project.json" >/dev/null 2>&1
+assert "v1.0→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['version']=='1.4'\""
+assert "v1.0→v1.4: has preferences" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert 'preferences' in d\""
+assert "v1.0→v1.4: preserves project_name" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['project_name']=='Test Course v1.0'\""
+
+# --- Test: v1.2 → v1.4 migration ---
+cp "$FIXTURE_DIR/manifest-v1.2.json" "$WORK/project.json"
+"$MIGRATE" "$WORK/project.json" >/dev/null 2>&1
+assert "v1.2→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['version']=='1.4'\""
+assert "v1.2→v1.4: has preferences" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['preferences']['verbosity']=='normal'\""
+
+# --- Test: idempotent ---
+assert "v1.2→v1.4: idempotent" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['version']=='1.4'\" && '$MIGRATE' '$WORK/project.json' >/dev/null 2>&1 && python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['version']=='1.4'\""
+
+# --- Test: v1.3-drifted → v1.4 cleanup migration ---
+if [ -f "$FIXTURE_DIR/manifest-v1.3-drifted.json" ]; then
+  cp "$FIXTURE_DIR/manifest-v1.3-drifted.json" "$WORK/project.json"
+  "$MIGRATE" "$WORK/project.json" >/dev/null 2>&1
+  assert "v1.3-drifted→v1.4: version bumped" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert d['version']=='1.4'\""
+  assert "v1.3-drifted→v1.4: red_team summary renamed to findings_summary" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); rt=d['red_team_audit']; assert 'summary' not in rt; assert rt['findings_summary']=={'critical': 3, 'warning': 5, 'info': 2}\""
+  assert "v1.3-drifted→v1.4: _import_quality_flags moved into import_metadata" "python3 -c \"import json; d=json.load(open('$WORK/project.json')); assert '_import_quality_flags' not in d; details=d['import_metadata']['quality_flag_details']; assert len(details)==2 and details[0]['key']=='orphan_module_8'\""
+fi
+
+# --- Test: file does not exist ---
+rm -f "$WORK/project.json"
+"$MIGRATE" "$WORK/project.json" >/dev/null 2>&1
+EC=$?
+assert "missing manifest exits 0" "[ $EC -eq 0 ]"
+
+# --- Test: malformed json gracefully degraded (fallback to cat, exits 0) ---
+echo "invalid json" > "$WORK/project.json"
+# capture output to check fallback mechanism
+OUT=$("$MIGRATE" "$WORK/project.json" 2>/dev/null)
+EC=$?
+assert "malformed manifest exits 0" "[ $EC -eq 0 ]"
+assert "malformed manifest outputs original" "[ \"\$OUT\" = 'invalid json' ]"
+
+echo ""
+echo "migrate: $PASS/$TOTAL passed, $FAIL failed"
+[ "$FAIL" -eq 0 ] && exit 0 || exit 1