feat(q3): 贝叶斯网格粒子滤波闭环（PF负观测+信息增益选点+2-opt调度）

- particles.py: 网格幸存集滤波，Voronoi 裕量保证真源保留（缺席证明/网格清除证书/跳测规则）
- planner/bayes_loop.py: 统一任务循环（站点/定位/清除滚动 2-opt 排序）、期望后验半径选点
- planner/seven.py: 七点覆盖策略族提升为库代码
- cli: mcm26b run --strategy {grid,seven,bayes}
- BayesConfig 参数组；tests +24 项（真源保留/证书/端到端），129 全绿

tests/test_bayes_loop_q3.py

@@ -0,0 +1,154 @@
+"""P4b 贝叶斯闭环端到端验收：全清、PF 缺席证明、预算与故障。
+
+对齐 test_loop_q3.py 的验收口径（docs/algo-3-bayes.md）：
+- 10/16 源场景全部清除且守恒性零异常（凸证书 + 网格证书均不得失效）；
+- PF 缺席证明（幸存集为空）与覆盖账本口径一致，不误判有源频道；
+- 无源场景全部频道证明缺席后正常退出（persistent 关闭时 all_resolved）；
+- 近圆域边界源（r_eff=1000）不漏搜；
+- 持续复扫（persistent 默认开）：找全后复扫到虚拟安全余量，
+  accounted_virtual_time_s 记录首次证明找全时刻；
+- 网络故障幂等重试不污染闭环结果；
+- 虚拟时刻逐步复算一致。
+"""
+
+import math
+import unittest
+from dataclasses import replace
+
+from mcm26b.config import ProblemConfig
+from mcm26b.evaluation import recompute_virtual_time
+from mcm26b.planner.bayes_loop import BayesLoop
+from mcm26b.protocol.client import SimulatorClient
+from mcm26b.sim import (LocalSimTransport, LocalSimulator,
+                        ScriptedFaultTransport, Source)
+from mcm26b.sim.scenes import random_omni_scene
+
+CONFIG = replace(ProblemConfig(),
+                 search=replace(ProblemConfig().search,
+                                bearing_rounding_margin_deg=0.005))
+SMALL_CAP = replace(CONFIG,
+                    field=replace(CONFIG.field, max_virtual_duration_s=60_000.0))
+NO_PERSIST = replace(CONFIG, search=replace(CONFIG.search,
+                                            persistent_search=False))
+
+
+def _run_scene(sources, fault_script=None, config=SMALL_CAP):
+    simulator = LocalSimulator(sources, robot_id="T001", config=config)
+    transport = LocalSimTransport(simulator)
+    if fault_script is not None:
+        transport = ScriptedFaultTransport(transport, fault_script)
+    client = SimulatorClient("T001", config=config, transport=transport)
+    loop = BayesLoop(client, config)
+    summary = loop.run()
+    report = recompute_virtual_time(client.log.action_events())
+    return summary, report, simulator
+
+
+class BayesLoopAcceptanceTests(unittest.TestCase):
+    def test_ten_sources_all_cleared(self):
+        sources = random_omni_scene(seed=5, count=10, config=CONFIG)
+        summary, report, simulator = _run_scene(sources)
+        truth = sorted(s.channel for s in sources)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(sorted(summary["cleared_channels"]), truth)
+        self.assertEqual(summary["unresolved_channels"], [])
+        self.assertIsNotNone(summary["accounted_virtual_time_s"])
+        self.assertEqual(summary["anomalies"], [], "守恒性或证书不应被打破")
+        self.assertEqual(report["mismatches"], [])
+        self.assertEqual(sorted(simulator.cleared), truth)
+        self.assertEqual(summary["exit_reason"], "user_exit")
+        self.assertEqual(summary["strategy"], "bayes")
+
+    def test_sixteen_sources_stop_by_count_bound(self):
+        sources = random_omni_scene(seed=6, count=16, config=CONFIG)
+        summary, report, simulator = _run_scene(sources)
+        truth = sorted(s.channel for s in sources)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(summary["stop_reason"], "sixteen_cleared")
+        self.assertEqual(sorted(summary["cleared_channels"]), truth)
+        self.assertEqual(report["mismatches"], [])
+        self.assertEqual(summary["anomalies"], [])
+
+    def test_empty_arena_all_absent(self):
+        """0 源：每个频道都必须由 PF 排除盘证明缺席后正常退出。"""
+        summary, report, simulator = _run_scene([], config=NO_PERSIST)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(summary["stop_reason"], "all_resolved")
+        self.assertEqual(sorted(summary["absent_channels"]),
+                         list(range(1, 21)))
+        self.assertEqual(summary["pf_absent_channels"], list(range(1, 21)))
+        self.assertEqual(summary["clears"], 0)
+        self.assertEqual(summary["anomalies"], [])
+        self.assertEqual(report["mismatches"], [])
+
+    def test_boundary_sources_detected_and_cleared(self):
+        """近圆域边界源（r_eff=1000）：七站覆盖半径 968.9m 保证发现。"""
+        sources = [Source(c + 1, 1800.0 * math.cos(math.pi / 6 + 2 * math.pi * c / 4),
+                          1800.0 * math.sin(math.pi / 6 + 2 * math.pi * c / 4),
+                          1000.0) for c in range(4)]
+        summary, report, simulator = _run_scene(sources, config=NO_PERSIST)
+        truth = sorted(s.channel for s in sources)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(sorted(summary["cleared_channels"]), truth)
+        self.assertEqual(summary["anomalies"], [])
+        self.assertEqual(report["mismatches"], [])
+
+    def test_persistent_phase_resweeps_until_cap(self):
+        """找全后持续复扫到虚拟安全余量 [用户决策 2026-09-11]。"""
+        sources = random_omni_scene(seed=5, count=10, config=CONFIG)
+        summary, _report, _simulator = _run_scene(sources, config=SMALL_CAP)
+        truth = sorted(s.channel for s in sources)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(summary["stop_reason"], "virtual_time_cap")
+        self.assertEqual(sorted(summary["cleared_channels"]), truth)
+        self.assertGreater(summary["measures"], 7 * 20,
+                           "找全后应继续复扫未清除频道")
+
+    def test_transport_fault_retries_keep_session_clean(self):
+        sources = random_omni_scene(seed=5, count=10, config=CONFIG)
+        script = [("drop_before", 1)]   # 首个请求丢弃一次：幂等重试路径
+        summary, report, simulator = _run_scene(sources, fault_script=script)
+        truth = sorted(s.channel for s in sources)
+        self.assertTrue(summary["completed"])
+        self.assertEqual(sorted(summary["cleared_channels"]), truth)
+        self.assertEqual(report["mismatches"], [])
+
+    def test_skip_rule_never_skips_detectable_channel(self):
+        """跳测规则只允许跳过"必 no_signal"的 (站,频道) 对。"""
+        sources = random_omni_scene(seed=5, count=10, config=CONFIG)
+        simulator = LocalSimulator(sources, robot_id="T001", config=CONFIG)
+        client = SimulatorClient("T001", config=CONFIG,
+                                 transport=LocalSimTransport(simulator))
+        loop = BayesLoop(client, CONFIG)
+        loop.run()
+        from mcm26b.belief import ChannelStatus
+        for index, point in enumerate(loop.ledger.points):
+            for channel, belief in loop.belief.channels.items():
+                if belief.status is not ChannelStatus.UNKNOWN:
+                    continue
+                skipped = loop._skip_station_channel(channel, index, point)
+                if skipped and len(loop.particles[channel]):
+                    nearest = loop.particles[channel].nearest_alive_distance(
+                        point, loop.particles[channel].r_eff_max_m
+                        + loop.particles[channel].margin_m)
+                    self.assertIsNone(
+                        nearest, f"频道 {channel} 站点 {index} 被跳过但可能检出")
+
+    def test_cli_strategy_registry(self):
+        """CLI --strategy 注册表：bayes/seven 用七站，grid 用 49 点网格。"""
+        import mcm26b.cli as cli
+        from mcm26b.coverage import coverage_points
+        from mcm26b.planner.seven import SevenBatch, seven_points
+        self.assertIs(cli.Q3_STRATEGIES["bayes"], BayesLoop)
+        for name, loop_cls in cli.Q3_STRATEGIES.items():
+            simulator = LocalSimulator([], robot_id="T001", config=CONFIG)
+            client = SimulatorClient("T001", config=CONFIG,
+                                     transport=LocalSimTransport(simulator))
+            loop = loop_cls(client, CONFIG)
+            expected = seven_points() if name in ("bayes", "seven") \
+                else coverage_points(CONFIG)
+            self.assertEqual(loop.ledger.points, expected)
+
+
+if __name__ == "__main__":
+    unittest.main()