feat(v2): T05-c 运行补充说明只能形成草稿（AC-26）

运行时的"本次预审补充说明"只影响本次运行（run_instruction 落在运行对象上，
属 T07 的 ScreeningRun 字段）。要变成持久知识只有一条路：显式提议为草稿，
且走正常审核。本批实现卡片侧的那一半。

新增 knowledge_cards.draft_from_run_instruction()，三条约束：
1. 只产草稿——运行中说过的话绝不直接生效（有测试断言无已发布版本产生）
2. **不得携带工具/权限/引擎字段**：allowed_tools / tools / permissions / engine /
   run_instruction 出现即拒，扩大工具授权必须走独立提议与审核
3. 记录 derived_from_run，便于回溯知识来自哪次运行
另：运行指令不能声明为 history_derived（历史提炼须提供来源事件或证据），
hard 门禁对运行衍生的卡片同样生效。

未完成：运行对象上的 run_instruction 字段与"只影响本次运行"的服务端实现属 T07，
本批只交付卡片侧，不宣称 AC-26 已整体闭环。

测试：test_knowledge_cards.py 增至 25 项（新增 5 项）。
全量 315 项 OK（310 → 315）；verify.py 10/10 PASS。

Co-Authored-By: Claude Code <noreply@anthropic.com>

backend/test_knowledge_cards.py

@@ -220,5 +220,47 @@ class EffectiveFilterTests(KnowledgeCardTestCase):
                 self.assertIn("不是项目知识卡片", str(ctx.exception))
 
 
+class RunInstructionScopeTests(KnowledgeCardTestCase):
+    """AC-26：运行补充说明只影响当前运行；持久化只能形成草稿，且不得扩大工具权限。"""
+
+    def draft_from_run(self, body, actor="demo-manager"):
+        with store.transaction(self.db_path) as db:
+            return cards.draft_from_run_instruction(db, "DEMO-A", "run-1", body, actor)
+
+    def test_instruction_becomes_a_draft_never_a_published_card(self):
+        draft = self.draft_from_run(rule_body(id="corporate.from_run"))
+        self.assertEqual(draft["status"], "draft")
+        with store.transaction(self.db_path) as db:
+            published = [row for row in store.listing(db, "component_version")
+                         if row.get("component_id") == "corporate.from_run"]
+        self.assertEqual(published, [], "运行中说过的话不得直接成为生效知识")
+
+    def test_instruction_cannot_widen_tool_permissions(self):
+        for field in ("allowed_tools", "tools", "permissions", "engine", "run_instruction"):
+            with self.subTest(field=field):
+                body = rule_body(id="corporate.tool_grab")
+                body[field] = ["terminal"]
+                with self.assertRaises(ValueError) as ctx:
+                    self.draft_from_run(body)
+                self.assertIn("不能持久化工具权限", str(ctx.exception))
+
+    def test_instruction_cannot_claim_history_derived_origin(self):
+        with self.assertRaises(ValueError) as ctx:
+            self.draft_from_run(rule_body(id="corporate.fake_history", origin="history_derived"))
+        self.assertIn("不能声明为历史提炼", str(ctx.exception))
+
+    def test_draft_records_which_run_it_came_from(self):
+        mock = self.draft_from_run(rule_body(id="corporate.traced"))
+        with store.transaction(self.db_path) as db:
+            row = store.get(db, "component_draft", mock["id"])
+        self.assertEqual(row["derived_from_run"], "run-1")
+        self.assertEqual(row["proposed_via"], "run_instruction")
+
+    def test_hard_gate_still_applies_to_run_derived_cards(self):
+        with self.assertRaises(ValueError) as ctx:
+            self.draft_from_run(rule_body(id="corporate.run_hard", effect="hard"))
+        self.assertIn("正式制度或授权依据", str(ctx.exception))
+
+
 if __name__ == "__main__":
     unittest.main()