fix(panel): prefer the freshest phase signal when heartbeat lags

The agent occasionally forgets to flip the .phase heartbeat on transition;
when the objective disk evidence (registry/.summaries/.manifest mtime) is
newer than the heartbeat file, trust the disk. Seen live: heartbeat stuck
at 采集中 while manifest had landed 3 minutes earlier.

web/app.py

@@ -561,34 +561,11 @@ def _harvest_phase(source):
     """返回正在运行任务的 (开始时间, 阶段名)。
 
     阶段以真实信号为准,不做推测:
-    1. <source>.phase 文件 —— harvest.sh 写初始"采集中",采集会话每进入新阶段
-       即时更新(采集中/摘要生成/推送收尾),任务退出时删除;
-    2. 兜底用当日目录磁盘信号(registry/.summaries/.manifest 的 mtime);
+    1. <source>.phase 心跳文件 —— harvest.sh 写初始"采集中",采集会话每进入
+       新阶段即时更新;仅当它不比磁盘证据旧时采信(会话偶尔忘翻牌);
+    2. 当日目录磁盘信号(registry/.summaries/.manifest 的 mtime)是客观事实;
     3. 都没有 → 中性"运行中"。
     """
-    port = _site_cdp_port(source.split("-")[0])
-    lockdir = WORK_DIR / "runlocks"
-    if not lockdir.is_dir():
-        return None, None
-    locks = list(lockdir.glob(f"port-{port}.*.lock"))
-    if not locks:
-        return None, None
-    try:
-        start = datetime.fromtimestamp(locks[0].stat().st_mtime)
-    except OSError:
-        return None, None
-
-    # 1) 真实阶段文件(进程自己写的)
-    phase_file = LOG_DIR / f"{source}.phase"
-    if phase_file.exists():
-        try:
-            txt = phase_file.read_text(encoding="utf-8").strip()
-        except OSError:
-            txt = ""
-        if txt:
-            return start, txt
-
-    # 2) 磁盘信号兜底(仍是事实,非推测)
     def mtime(p):
         try:
             return datetime.fromtimestamp(p.stat().st_mtime)
@@ -603,16 +580,49 @@ def _harvest_phase(source):
             src.get("vaultFolder", "") / datetime.now().strftime("%Y%m%d")
     except (StopIteration, ValueError, OSError):
         day_dir = None
-    if day_dir and day_dir.is_dir():
+    port = _site_cdp_port(source.split("-")[0])
+    lockdir = WORK_DIR / "runlocks"
+    if not lockdir.is_dir():
+        return None, None
+    locks = list(lockdir.glob(f"port-{port}.*.lock"))
+    if not locks:
+        return None, None
+    try:
+        start = datetime.fromtimestamp(locks[0].stat().st_mtime)
+    except OSError:
+        return None, None
+
+    # 1) 真实阶段文件(进程自己写的)——但仅当它比磁盘证据新时才采信
+    #    (会话偶尔忘记翻牌,磁盘信号(manifest/summaries/registry)是客观事实)
+    def disk_phase_and_mtime():
+        if not (day_dir and day_dir.is_dir()):
+            return None, None
         reg = mtime(day_dir / "registry.json")
         if reg and reg > start:
-            return start, "推送/收尾"
+            return "推送/收尾", reg
         summ = mtime(day_dir / ".summaries.json")
         if summ and summ > start:
-            return start, "摘要生成"
+            return "摘要生成", summ
         mani = mtime(day_dir / ".manifest.json")
         if mani and mani > start:
-            return start, "摘要生成"
+            return "摘要生成", mani
+        return None, None
+
+    phase_file = LOG_DIR / f"{source}.phase"
+    hb_txt, hb_mtime = "", None
+    if phase_file.exists():
+        try:
+            hb_txt = phase_file.read_text(encoding="utf-8").strip()
+            hb_mtime = mtime(phase_file)
+        except OSError:
+            hb_txt, hb_mtime = "", None
+    dp, dp_mtime = disk_phase_and_mtime()
+    if hb_txt and hb_mtime:
+        if not dp or hb_mtime >= dp_mtime:
+            return start, hb_txt
+        return start, dp  # 心跳比磁盘证据旧:信磁盘
+    if dp:
+        return start, dp
     # 3) 无信号:中性显示,不猜
     return start, "运行中"