fix(client): wait for PDD foreground after intent

client/src/cmbuyer_client/pdd/product_open.py

@@ -7,9 +7,11 @@ from dataclasses import dataclass
 from datetime import UTC, datetime
 from hashlib import sha256
 import json
+from math import isfinite
 import os
 from pathlib import Path
 import shutil
+from time import monotonic, sleep
 from typing import Any, Protocol
 from uuid import uuid4
 
@@ -40,7 +42,7 @@ class ProductVersionMismatchError(ProductOpenError):
 
 
 class ProductPackageMismatchError(ProductOpenError):
-    """Intent 后当前前台包不是拼多多。"""
+    """Intent 后在有限时间内未观察到拼多多前台包。"""
 
 
 class ProductOpenTimeoutError(ProductOpenError):
@@ -90,12 +92,20 @@ class ProductOpenCapturer:
         adb_client: AdbClient,
         connector: Callable[[str], ProductOpenUiDevice],
         timeout_seconds: float,
+        foreground_poll_interval_seconds: float = 0.2,
+        monotonic_clock: Callable[[], float] = monotonic,
+        sleep_function: Callable[[float], None] = sleep,
     ) -> None:
-        if timeout_seconds <= 0:
-            raise ValueError("timeout_seconds 必须大于 0")
+        if not _is_positive_finite(timeout_seconds):
+            raise ValueError("timeout_seconds 必须是大于 0 的有限数值")
+        if not _is_positive_finite(foreground_poll_interval_seconds):
+            raise ValueError("foreground_poll_interval_seconds 必须是大于 0 的有限数值")
         self._adb_client = adb_client
         self._connector = connector
         self._timeout_seconds = timeout_seconds
+        self._foreground_poll_interval_seconds = foreground_poll_interval_seconds
+        self._monotonic_clock = monotonic_clock
+        self._sleep_function = sleep_function
 
     def open_and_capture(self, serial: str, product_url: str, output_directory: Path) -> ProductOpenResult:
         """完成唯一允许的 Intent 打开及其后的只读取证。"""
@@ -114,7 +124,7 @@ class ProductOpenCapturer:
 
             # 版本精确匹配是 Intent 的前置条件，失败时绝不调用 start_pdd_view_intent。
             intent = self._adb_client.start_pdd_view_intent(serial, link.goods_id)
-            _require_pdd_foreground(device.app_current())
+            self._wait_for_pdd_foreground(device)
 
             target.parent.mkdir(parents=True, exist_ok=True)
             staging = target.parent / f".{target.name}.staging-{uuid4().hex}"
@@ -174,6 +184,21 @@ class ProductOpenCapturer:
             hierarchy_path=target / "hierarchy.xml",
         )
 
+    def _wait_for_pdd_foreground(self, device: ProductOpenUiDevice) -> None:
+        """只轮询当前 package，直到 deadline；Activity 和节点树均不参与本判据。"""
+
+        deadline = self._monotonic_clock() + self._timeout_seconds
+        while True:
+            if _is_pdd_foreground(device.app_current()):
+                return
+            remaining = deadline - self._monotonic_clock()
+            if remaining <= 0:
+                raise ProductPackageMismatchError(
+                    "商品链接打开后未在限定时间内进入拼多多，已停止后续取证。"
+                )
+            # 每个失败观察后都等待正的、受 deadline 约束的时长，避免 busy-loop。
+            self._sleep_function(min(self._foreground_poll_interval_seconds, remaining))
+
 
 def _validate_new_target(target: Path) -> None:
     if target.exists():
@@ -197,9 +222,12 @@ def _require_expected_version(app_info: dict[str, Any]) -> str:
     return version
 
 
-def _require_pdd_foreground(current: dict[str, Any]) -> None:
-    if not isinstance(current, dict) or current.get("package") != PDD_PACKAGE:
-        raise ProductPackageMismatchError("商品链接打开后前台应用不是拼多多，已停止后续取证。")
+def _is_positive_finite(value: object) -> bool:
+    return isinstance(value, (int, float)) and not isinstance(value, bool) and value > 0 and isfinite(value)
+
+
+def _is_pdd_foreground(current: object) -> bool:
+    return isinstance(current, dict) and current.get("package") == PDD_PACKAGE
 
 
 def _manifest(