fix(assignments): 未分配列表不再混入 CK 失效账号

分配池统一为：持 CK、CK 未判失效、未被停用/归档。新增 assignable_only 参数贯穿账号列表、批量分配与分配概览；前端列表与一键全部分配使用同一口径。

tests/test_account_assign_filter.py

@@ -14,7 +14,11 @@
 
 from tests.support.db import get_test_engine, make_test_session
 from web.backend.models import Account, User
-from web.backend.routers.accounts import batch_assign_accounts, list_accounts
+from web.backend.routers.accounts import (
+    assignments_summary,
+    batch_assign_accounts,
+    list_accounts,
+)
 from web.backend.schemas import BatchAssign
 
 
@@ -97,6 +101,66 @@ class TestAssignFilter(_Base):
         assert self.names(assign_status="unassigned", tag="10.1-测试") == ["tag-a-free"]
 
 
+class TestAssignablePool(_Base):
+    """分配池口径：CK 失效的号必须先修复，不能混进「未分配」让人误分配。"""
+
+    def test_assignable_only_excludes_invalid_ck(self):
+        self.make_account("ap-valid", ck_check_status="valid")
+        self.make_account("ap-unchecked")  # 还没检测过：按可用处理
+        self.make_account("ap-error", ck_check_status="error")  # 查不到 ≠ 失效
+        self.make_account("ap-invalid", ck_check_status="invalid")
+        self.make_account("ap-disabled", ck_check_status="valid", status="disabled")
+
+        assert self.names(assign_status="unassigned", assignable_only=True) == [
+            "ap-valid",
+            "ap-unchecked",
+            "ap-error",
+        ]
+
+    def test_summary_counts_only_assignable(self):
+        self.make_account("as-valid", ck_check_status="valid")
+        self.make_account("as-invalid", ck_check_status="invalid")
+        self.make_account(
+            "as-assigned-valid", ck_check_status="valid", assigned_to=self.support.id
+        )
+        self.make_account(
+            "as-assigned-invalid",
+            ck_check_status="invalid",
+            assigned_to=self.support.id,
+        )
+
+        summary = assignments_summary(db=self.session, current=self.admin)
+
+        assert summary["unassigned_count"] == 1
+        assert summary["assigned_count"] == 1
+        assert summary["total_count"] == 2
+        support = next(
+            u for u in summary["support_users"] if u["id"] == self.support.id
+        )
+        assert support["assigned_count"] == 1
+
+    def test_all_matching_assignable_only_skips_invalid(self):
+        valid = self.make_account("am-valid", ck_check_status="valid")
+        invalid = self.make_account("am-invalid", ck_check_status="invalid")
+
+        result = batch_assign_accounts(
+            BatchAssign(
+                all_matching=True,
+                assign_status="unassigned",
+                assignable_only=True,
+                assigned_to=self.support.id,
+            ),
+            db=self.session,
+            current=self.admin,
+        )
+
+        assert result["count"] == 1
+        self.session.refresh(valid)
+        self.session.refresh(invalid)
+        assert valid.assigned_to == self.support.id
+        assert invalid.assigned_to is None
+
+
 class TestAllMatchingAssign(_Base):
     def test_assigns_every_matching_unassigned(self):
         free = [self.make_account(f"mf-{i}") for i in range(3)]