Auto headless + Xvfb for headless servers

Enable Chromium on machines without DISPLAY: Python auto headless
with Xvfb hints, and start.sh installs/starts Xvfb (xvfb-run or
persistent :99) so registration can run headed under a virtual display.

auto_register.py

@@ -196,6 +196,13 @@ def resolve_browser_path() -> str | None:
     return None
 
 
+def has_display() -> bool:
+    """True if Chromium can open a real GUI window (Windows always; else DISPLAY/WAYLAND)."""
+    if sys.platform == "win32":
+        return True
+    return bool((os.environ.get("DISPLAY") or "").strip() or (os.environ.get("WAYLAND_DISPLAY") or "").strip())
+
+
 def create_browser_options(headless: bool = False, proxy: str = "") -> ChromiumOptions:
     opts = ChromiumOptions()
     opts.auto_port()
@@ -217,8 +224,26 @@ def create_browser_options(headless: bool = False, proxy: str = "") -> ChromiumO
             print("[!] skip turnstilePatch: Google Chrome disallows --load-extension; use Chromium")
         else:
             opts.add_extension(EXTENSION_PATH)
-    if headless:
-        opts.headless()
+    # Auto headless when no DISPLAY (unless caller already requested headless)
+    use_headless = bool(headless) or not has_display()
+    if use_headless:
+        try:
+            opts.headless()
+        except Exception:
+            opts.set_argument("--headless=new")
+        for flag in ("--headless=new", "--disable-gpu", "--no-sandbox", "--disable-dev-shm-usage"):
+            try:
+                opts.set_argument(flag)
+            except Exception:
+                pass
+        if not headless and not has_display():
+            print(
+                f"[*] 无图形界面 (DISPLAY={os.environ.get('DISPLAY', '')!r})，已自动启用 headless。\n"
+                "    推荐: xvfb-run -a python auto_register.py ...  （过 CF 更稳）",
+                flush=True,
+            )
+        else:
+            print("[*] browser headless=True", flush=True)
     if proxy:
         try:
             from urllib.parse import urlparse