feat: Linux 真实实现层 — 从存根库变为可用生产力工具

新增 _linux_impl.py (800+行):
- LinuxNetwork: 真实IP/接口/DNS/网关/MAC (ip命令+/proc/net)
- LinuxBluetooth: 真实蓝牙状态/扫描/配对/连接 (bluetoothctl)
- LinuxSensors: 真实温度/CPU频率/风扇 (/sys/class/hwmon)
- LinuxAudio: 真实音量控制/静音 (amixer)
- LinuxClipboard: 真实剪贴板读写 (xclip+tkinter回退)
- LinuxPower: 真实CPU/内存/电池 (psutil+/sys/class/power_supply)
- LinuxLocation: 真实IP地理定位 (ip-api.com)
- LinuxNotify: 真实桌面通知 (notify-send)
- LinuxDisplay: 真实屏幕尺寸/截屏/鼠标位置 (xdotool+X11)
- LinuxUIAutomation: 真实点击/输入/按键/滚动 (xdotool)
- LinuxCamera: 真实摄像头拍照 (opencv/V4L2)
- LinuxProcess: 真实进程列表/系统信息/应用管理 (psutil+/proc)
- LinuxShell: 真实命令执行 (subprocess)

改造10+核心类使用Linux真实实现:
- BluetoothAdapter/SensorManager/AudioManager
- ConnectivityManager/WifiManager/TelephonyManager
- LocationManager/PowerManager/BatteryManager/Build
- ActivityManager/Activity/Toast/Display/ClipboardManager
- NotificationManager

15项真实行为测试全部通过:
- 真实IP: 10.60.218.244
- 真实位置: 北京 39.9042, 116.407
- 真实主机名: work-41-vci-g427c
- 真实内核: 5.15.120.byteatom-ck.14
- 真实内存: 1.8GB/3.8GB
- 真实进程列表

android_pyapi/android/net_ext.py

@@ -15,6 +15,13 @@ from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
 
 from .._core import Stub, AndroidOnlyError
 
+# Linux 真实实现导入
+try:
+    from .._linux_impl import IS_LINUX, LinuxNetwork, HAS_IP
+    _USE_LINUX = IS_LINUX
+except ImportError:
+    _USE_LINUX = False
+
 __all__ = [
     "Network", "NetworkCapabilities", "NetworkRequest", "NetworkSpecifier",
     "MatchAllNetworkSpecifier", "NetworkAgent", "NetworkInfo",
@@ -1291,17 +1298,64 @@ class ConnectivityManager(Stub):
     def getActiveNetwork(self) -> Optional[Network]:
         return self._active_network
 
+    def _get_linux_active_info(self):
+        """从 Linux 真实网络信息构造活跃 NetworkInfo"""
+        try:
+            from .net import NetworkInfo
+            interfaces = LinuxNetwork.get_interfaces()
+            # 有真实网络接口 (非环回) 且 operstate=up 即视为已连接
+            connected = any(
+                (iface.get("ifname") or iface.get("name", "")) != "lo"
+                and iface.get("operstate", "").lower() == "up"
+                for iface in interfaces
+            )
+            if not connected:
+                connected = LinuxNetwork.get_connectivity()
+            ip = LinuxNetwork.get_ip_address()
+            iface_name = ""
+            net_type = ConnectivityManager.TYPE_ETHERNET
+            for iface in interfaces:
+                name = iface.get("ifname") or iface.get("name", "")
+                state = iface.get("operstate", "")
+                if name and name != "lo" and state.lower() == "up":
+                    iface_name = iface_name or name
+                if name and name.startswith(("wl", "wlan", "wlp")):
+                    net_type = ConnectivityManager.TYPE_WIFI
+                    iface_name = name
+            data = {
+                "connected": connected,
+                "ip": ip,
+                "interface": iface_name,
+                "type_name": "WIFI" if net_type == ConnectivityManager.TYPE_WIFI else "ETHERNET",
+            }
+            return NetworkInfo.from_linux_data(data, network_type=net_type)
+        except Exception:
+            return None
+
     def getActiveNetworkInfo(self) -> Optional[NetworkInfo]:
+        if _USE_LINUX:
+            return self._get_linux_active_info()
         if self._active_network:
             return self._network_infos.get(self._active_network.getNetId())
         return None
 
     def getNetworkInfo(self, networkType: int) -> Optional[NetworkInfo]:
+        if _USE_LINUX:
+            info = self._get_linux_active_info()
+            if info is not None and info.getType() == networkType:
+                return info
+            return None
         for info in self._network_infos.values():
             if info.getType() == networkType:
                 return info
         return None
 
+    def getConnectivityStatus(self) -> bool:
+        """返回当前网络连通性 (True=已连接)"""
+        if _USE_LINUX:
+            return LinuxNetwork.get_connectivity()
+        return self._active_network is not None
+
     def getNetworkInfoForNetwork(self, network: Network) -> Optional[NetworkInfo]:
         return self._network_infos.get(network.getNetId())