修正桌面啟動時的 No session for pid：停用 lxpolkit/light-locker autostart

README.md

@@ -53,6 +53,8 @@ OpenCode 在啟動時安裝，並重設使用者層級設定為預設值。
   重複的程序會被清掉。
 - 桌面裡永遠有一個標題為「共用終端機」的 xterm；把它關掉後看門狗會自動再開一個，
   所以固定分頁裡永遠有 1 個可用的圖形終端機視窗（使用者自己另開的终端機不受影響）。
+- 容器內沒有 systemd-logind session，因此會自動停用 `lxpolkit` 與 `light-locker`
+  autostart，避免桌面啟動時跳出「No session for pid …」的 Error 對話框。
 - 瀏覽器是透過 `/vnc` WebSocket 橋接到同一個桌面，所有裝置看到完全相同、可同時操作的
   LXDE 畫面；關掉瀏覽器分頁不會終止桌面，重新整理或重新連線都會接回原畫面。
 - 這個分頁是固定的：按它的 `×` 不會刪除分頁，而是重新啟動一份新的桌面

app.py

@@ -1460,6 +1460,79 @@ class DesktopManager:
     def _term_binary(self):
         return shutil.which("xterm") or shutil.which("lxterminal")
 
+    def _prepare_session_config(self):
+        """關掉容器裡必然失敗的 polkit / 螢幕鎖定 autostart，避免出現
+        「No session for pid …」的 Error 對話框（Xvfb 沒有 logind session）。"""
+        autostart = os.path.join(HOME, ".config", "autostart")
+        try:
+            os.makedirs(autostart, exist_ok=True)
+            for name in ("lxpolkit", "light-locker"):
+                path = os.path.join(autostart, name + ".desktop")
+                content = (
+                    "[Desktop Entry]\n"
+                    "Type=Application\n"
+                    f"Name={name}\n"
+                    "Exec=/bin/true\n"
+                    "Hidden=true\n"
+                    "NoDisplay=true\n"
+                    "X-GNOME-Autostart-enabled=false\n"
+                )
+                if not (os.path.isfile(path) and open(path).read() == content):
+                    with open(path, "w") as f:
+                        f.write(content)
+        except OSError as exc:
+            self._log(f"無法寫入 autostart 覆寫：{exc}", logging.WARNING)
+
+        system_conf = "/etc/xdg/lxsession/LXDE/desktop.conf"
+        user_conf = os.path.join(HOME, ".config", "lxsession", "LXDE", "desktop.conf")
+        source = user_conf if os.path.isfile(user_conf) else system_conf
+        try:
+            if not os.path.isfile(source):
+                return
+            with open(source) as f:
+                lines = f.read().splitlines()
+            changed = False
+            out = []
+            for line in lines:
+                if line.startswith("polkit/command=") and line != "polkit/command=":
+                    line = "polkit/command="
+                    changed = True
+                elif line.startswith("lock_manager/command=") and line != "lock_manager/command=":
+                    line = "lock_manager/command="
+                    changed = True
+                out.append(line)
+            if changed or source != user_conf:
+                os.makedirs(os.path.dirname(user_conf), exist_ok=True)
+                with open(user_conf, "w") as f:
+                    f.write("\n".join(out) + "\n")
+        except OSError as exc:
+            self._log(f"無法寫入 lxsession 設定：{exc}", logging.WARNING)
+
+    def _suppress_session_popups(self):
+        """保險：如果 lxpolkit / light-locker 還是被拉起來，直接關掉（不影響桌面）。"""
+        pids = []
+        try:
+            entries = os.listdir("/proc")
+        except OSError:
+            return
+        for entry in entries:
+            if not entry.isdigit():
+                continue
+            pid = int(entry)
+            if pid == os.getpid():
+                continue
+            cmd = self._cmdline(pid)
+            if not cmd:
+                continue
+            low = cmd.lower()
+            if not any(name in low for name in ("lxpolkit", "light-locker")):
+                continue
+            if DESKTOP_DISPLAY in cmd or self._has_display(pid):
+                pids.append(pid)
+        if pids:
+            self._log(f"關閉容器內無效的 session 元件：{pids}")
+            self._kill_pids(pids, signal.SIGKILL)
+
     def _kill_pids(self, pids, sig=signal.SIGTERM):
         for pid in pids:
             if not self._pid_alive(pid):
@@ -1544,6 +1617,7 @@ class DesktopManager:
         return True
 
     async def _start_session(self) -> bool:
+        self._prepare_session_config()
         last_error = "找不到 startlxde / lxsession / openbox"
         for launcher in ("startlxde", "lxsession", "openbox"):
             path = shutil.which(launcher)
@@ -1563,6 +1637,8 @@ class DesktopManager:
             if pid:
                 self.pids["session"] = pid
                 self._log(f"LXDE session 就緒（{launcher}，pid {pid}）")
+                await asyncio.sleep(0.5)
+                await asyncio.to_thread(self._suppress_session_popups)
                 return True
             last_error = f"{launcher} 啟動後立即結束（returncode={proc.poll()}）"
             self._log(last_error, logging.WARNING)
@@ -1601,7 +1677,8 @@ class DesktopManager:
             return True
         name = os.path.basename(binary)
         if name == "xterm":
-            argv = [binary, "-u8", "-geometry", "110x32+50+50",
+            argv = [binary, "-u8", "-fa", "DejaVu Sans Mono", "-fs", "11",
+                    "-geometry", "110x32+50+50",
                     "-T", self.TERM_TITLE, "-e", "bash", "--login"]
         else:
             argv = [binary, "--title=" + self.TERM_TITLE, "-e", "bash --login"]
@@ -1633,6 +1710,7 @@ class DesktopManager:
         if not await self._start_vnc():
             return False
         await self._start_term()
+        await asyncio.to_thread(self._suppress_session_popups)
         self.started_at = time.time()
         if self._healthy():
             self.last_error = ""