feat(xiaohongshu): multi-backend — OpenCLI / xiaohongshu-mcp / xhs-cli

- backends becomes the ordered candidate list [OpenCLI, xiaohongshu-mcp,
  xhs-cli]; probing order makes the desktop/server split automatic:
  OpenCLI never probes alive headless, so servers fall through to
  xiaohongshu-mcp; first fully-usable candidate wins, fixable (warn)
  candidates only win when nothing is fully usable
- xiaohongshu-mcp probing: HTTP reachability of localhost:18060
  (proxy-bypassed) + mcporter config presence; guides through
  `mcporter config add` when half-wired
- opencli backend: treat a sleeping extension service worker as ready —
  verified live that `daemon status` reports disconnected while any real
  command wakes it; disambiguate "sleeping" vs "never installed" via the
  Chrome Extensions directory on disk (fixes active_backend flapping
  between OpenCLI and xhs-cli across doctor runs)
- install: desktop installs OpenCLI; server prints the xiaohongshu-mcp
  guide (binary to ~/.agent-reach/tools/, QR login, mcporter add);
  xhs-cli is no longer installed by default (upstream unmaintained since
  2026-03) but existing installs keep working as the last candidate
- skill/references/social.md: xiaohongshu section rewritten as three
  backend command groups keyed off `doctor --json` active_backend,
  including the 120s-timeout and login-first caveats for the mcp path

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_opencli_backend.py

@@ -7,8 +7,8 @@ from agent_reach.backends import opencli_status, opencli_summary
 from agent_reach.probe import ProbeResult
 
 
-def _status_with(version_probe, daemon_probe=None):
-    """Run opencli_status with probe_command patched per call."""
+def _status_with(version_probe, daemon_probe=None, ext_on_disk=False):
+    """Run opencli_status with probe_command and disk check patched."""
     calls = []
 
     def fake_probe(cmd, args=("--version",), **kwargs):
@@ -17,7 +17,11 @@ def _status_with(version_probe, daemon_probe=None):
             return version_probe
         return daemon_probe or ProbeResult("missing")
 
-    with patch("agent_reach.backends.opencli.probe_command", side_effect=fake_probe):
+    with patch("agent_reach.backends.opencli.probe_command", side_effect=fake_probe), \
+         patch(
+             "agent_reach.backends.opencli._extension_installed_on_disk",
+             return_value=ext_on_disk,
+         ):
         return opencli_status(), calls
 
 
@@ -46,17 +50,34 @@ def test_daemon_running_extension_connected_is_ready():
     assert "1.8.3" in opencli_summary(st)
 
 
-def test_extension_disconnected_not_ready_with_store_guide():
+def test_extension_never_installed_not_ready_with_store_guide():
     daemon_out = "Daemon: running (PID 1)\nExtension: disconnected\n"
     st, _ = _status_with(
         ProbeResult("ok", output="1.8.3"),
         ProbeResult("ok", output=daemon_out),
+        ext_on_disk=False,
     )
     assert st.daemon_running and not st.extension_connected
     assert not st.ready
     assert "chromewebstore.google.com" in st.hint
 
 
+def test_sleeping_extension_counts_as_ready():
+    """实测:扩展 service worker 睡眠时 daemon status 报 disconnected,
+    但任何真实命令会唤醒它——装在磁盘上即视为可用。"""
+    daemon_out = "Daemon: running (PID 1)\nExtension: disconnected\n"
+    st, _ = _status_with(
+        ProbeResult("ok", output="1.8.3"),
+        ProbeResult("ok", output=daemon_out),
+        ext_on_disk=True,
+    )
+    assert not st.extension_connected
+    assert st.extension_installed
+    assert st.ready
+    assert "唤醒" in opencli_summary(st)
+    assert st.hint == ""
+
+
 def test_daemon_not_running_parsed_correctly():
     st, _ = _status_with(
         ProbeResult("ok", output="1.8.3"),