diff --git a/scripts/task.sh b/scripts/task.sh
index 164cafa4..4cfdccea 100755
--- a/scripts/task.sh
+++ b/scripts/task.sh
@@ -35,13 +35,20 @@ origin_transport_unavailable() { # $1=失败的远端命令 stderr → 仅明确
   esac
   [ ! -e "$path" ]
 }
-target_history() { # $1=可选基线（无缓存目标时代替比较，如任务 R0）→ 输出 ok（远端传输不可达/通告提交为基线后代）、rewound（回退或分叉）或 uncomparable（认证/授权/未知错误、目标 ref 缺失、无基线、通告提交本地缺失或无法比较）
-  local cached listing advertised rc=0
-  cached=$(git rev-parse -q --verify "refs/remotes/origin/${TARGET_BRANCH}^{commit}" 2>/dev/null) || cached=${1:-}
+target_history() { # $1=可选基线（如任务 R0；无缓存目标时代替比较）→ 输出 ok（通告提交为基线后代；传输不可达时缓存目标为基线后代或无缓存目标）、rewound（回退或分叉）或 uncomparable（认证/授权/未知错误、目标 ref 缺失、无基线、提交本地缺失或无法比较）
+  local base=${1:-} cached listing advertised rc=0
+  cached=$(git rev-parse -q --verify "refs/remotes/origin/${TARGET_BRANCH}^{commit}" 2>/dev/null) || cached=
   if ! listing=$(git ls-remote origin "refs/heads/${TARGET_BRANCH}" 2>&1); then
-    if origin_transport_unavailable "$listing"; then echo ok; else echo uncomparable; fi
+    if ! origin_transport_unavailable "$listing"; then echo uncomparable
+    elif [ -z "$cached" ]; then echo ok
+    elif [ -z "$base" ]; then echo uncomparable
+    else
+      git merge-base --is-ancestor "$base" "$cached" 2>/dev/null || rc=$?
+      case "$rc" in 0) echo ok ;; 1) echo rewound ;; *) echo uncomparable ;; esac
+    fi
     return 0
   fi
+  [ -n "$cached" ] || cached=$base
   advertised=$(printf '%s\n' "$listing" \
     | awk -v ref="refs/heads/${TARGET_BRANCH}" '$2 == ref && !seen { print $1; seen = 1 }')
   [ -n "$advertised" ] && [ -n "$cached" ] || { echo uncomparable; return 0; }
@@ -174,9 +181,8 @@ cmd_precheck() {
     exit 3
   fi
   if [ "$mode" = local ]; then
-    python3 "${SCRIPT_DIR}/evidence.py" --local-context --active || return 2
     if [ "$remote_fresh" -eq 0 ]; then
-      # 无缓存目标时只以活动任务卡登记的 R0 作比较基线，不把它当作远端最新值。
+      # 以活动任务卡登记的 R0 为比较基线（不把它当作远端最新值）；先于任务上下文核验，使缓存目标与 R0 矛盾时给出明确判定。
       case "$(target_history "$(card_r0 "$(branch_card "$branch")")")" in
         rewound)
           echo "[verdict] REMOTE_UNVERIFIED — origin/${TARGET_BRANCH} rewound or diverged from the known target; preserve local work and reconcile the target history"
@@ -186,6 +192,7 @@ cmd_precheck() {
           return 6 ;;
       esac
     fi
+    python3 "${SCRIPT_DIR}/evidence.py" --local-context --active || return 2
     [ "$remote_fresh" -eq 1 ] || echo "[remote-freshness] unavailable — LOCAL_READY rests on local task context only"
     echo "[verdict] LOCAL_READY — existing task may continue authorized local work; final delivery still requires latest-target sync and checks"
     return 0
diff --git a/tests/test_task_recovery.py b/tests/test_task_recovery.py
index ded3c923..ab2966db 100644
--- a/tests/test_task_recovery.py
+++ b/tests/test_task_recovery.py
@@ -1290,6 +1290,37 @@ class TaskRecoveryTests(unittest.TestCase):
                          "the task HEAD must not move when the precheck refuses to "
                          "advertise LOCAL_READY")
 
+    def test_local_outage_rejects_cached_target_diverged_from_r0(self):
+        """Origin transport is unavailable and the cached origin/main does not
+        descend from the registered R0. Local precheck must surface
+        REMOTE_UNVERIFIED and local resume must not import the receipt, instead
+        of continuing on a cache that already contradicts the task baseline."""
+        f = self.fixture
+        receipt = self.capture()
+        original = receipt.read_bytes()
+        card_before = self.card.read_bytes()
+        r0 = self.local_authorization_scope()["r0"]
+        divergent = f.git(self.wt, "commit-tree", r0 + "^{tree}", "-m",
+                          "Unrelated cached target").stdout.strip()
+        f.git(self.wt, "update-ref", "refs/remotes/origin/main", divergent)
+        self.assertEqual(f.git(self.wt, "merge-base", "--is-ancestor", r0, divergent,
+                               check=False).returncode, 1)
+        f.git(self.wt, "remote", "set-url", "origin", str(f.root / "missing.git"))
+        head_before = f.git(self.wt, "rev-parse", "HEAD").stdout
+
+        local = self.precheck()
+        self.assertNotEqual(local.returncode, 0, local.stdout)
+        self.assertIn("[verdict] REMOTE_UNVERIFIED", local.stdout)
+        self.assertIn("rewound or diverged", local.stdout)
+        self.assertNotIn("[verdict] LOCAL_READY", local.stdout)
+
+        resumed = self.resume(receipt)
+        self.assertNotEqual(resumed.returncode, 0, resumed.stdout)
+        self.assertNotIn("[resumed]", resumed.stdout)
+        self.assertEqual(self.card.read_bytes(), card_before)
+        self.assertEqual(receipt.read_bytes(), original)
+        self.assertEqual(f.git(self.wt, "rev-parse", "HEAD").stdout, head_before)
+
 
 if __name__ == "__main__":
     unittest.main()