feat(twitter): migrate from xreach to bird CLI

- Replace xreach CLI with bird (@steipete/bird) as Twitter/X backend
- bird uses AUTH_TOKEN/CT0 env vars (simpler than xreach's session.json)
- Accept both 'bird' and 'birdx' binary names
- Remove version detection logic (bird v0.8.0 is the baseline)
- Write credentials.env to ~/.config/bird/ for easy sourcing
- Keep xfetch session.json sync for backward compatibility
- Update SKILL.md commands: bird search/read/user-tweets/thread
- Update install/uninstall to use npm @steipete/bird
- All 52 tests pass

agent_reach/channels/twitter.py

@@ -1,76 +1,15 @@
 # -*- coding: utf-8 -*-
-"""Twitter/X — check if xreach CLI is available."""
+"""Twitter/X — check if bird CLI (@steipete/bird) is available."""
 
-import json
 import shutil
 import subprocess
 from .base import Channel
 
-# Minimum xreach-cli version with longform tweet and X Article support.
-# v0.3.2 added: extractTweetText() preferring note_tweet for long tweets (#aad6a16)
-# and X Article URL support (/article/ path, #2e05825).
-_MIN_XREACH_VERSION = (0, 3, 2)
-
-
-def _parse_version(ver_str: str) -> tuple[int, ...]:
-    """Parse a semver string like '0.3.2' into a tuple (0, 3, 2)."""
-    try:
-        return tuple(int(x) for x in ver_str.strip().split(".")[:3])
-    except (ValueError, AttributeError):
-        return (0, 0, 0)
-
-
-def _detect_xreach_version(xreach_path: str) -> str:
-    """Best-effort xreach version detection.
-
-    Some xreach-cli releases ship package.json@0.3.2 while `xreach --version`
-    still prints 0.3.0 because the embedded dist version file was not updated.
-    Prefer the newer of:
-    1) `xreach --version`
-    2) `npm list -g xreach-cli --json --depth=0`
-    """
-    versions: list[str] = []
-
-    try:
-        ver_result = subprocess.run(
-            [xreach_path, "--version"], capture_output=True,
-            encoding="utf-8", errors="replace", timeout=5
-        )
-        version_str = (ver_result.stdout or ver_result.stderr).strip()
-        if version_str:
-            versions.append(version_str)
-    except Exception:
-        pass
-
-    npm = shutil.which("npm")
-    if npm:
-        try:
-            npm_result = subprocess.run(
-                [npm, "list", "-g", "xreach-cli", "--json", "--depth=0"],
-                capture_output=True, encoding="utf-8", errors="replace", timeout=10,
-            )
-            if npm_result.returncode == 0 and npm_result.stdout:
-                data = json.loads(npm_result.stdout)
-                npm_ver = (
-                    data.get("dependencies", {})
-                    .get("xreach-cli", {})
-                    .get("version", "")
-                    .strip()
-                )
-                if npm_ver:
-                    versions.append(npm_ver)
-        except Exception:
-            pass
-
-    if not versions:
-        return ""
-    return max(versions, key=_parse_version)
-
 
 class TwitterChannel(Channel):
     name = "twitter"
     description = "Twitter/X 推文"
-    backends = ["xreach CLI"]
+    backends = ["bird CLI"]
     tier = 1
 
     def can_handle(self, url: str) -> bool:
@@ -79,36 +18,33 @@ class TwitterChannel(Channel):
         return "x.com" in d or "twitter.com" in d
 
     def check(self, config=None):
-        xreach = shutil.which("xreach")
-        if not xreach:
+        bird = shutil.which("bird") or shutil.which("birdx")
+        if not bird:
             return "warn", (
-                "xreach CLI 未安装。搜索可通过 Exa 替代。安装：\n"
-                "  npm install -g xreach-cli"
+                "bird CLI 未安装。搜索可通过 Exa 替代。安装：\n"
+                "  npm install -g @steipete/bird"
             )
-        # Check version — longform tweet support requires >= 0.3.2
-        try:
-            version_str = _detect_xreach_version(xreach)
-            version_tuple = _parse_version(version_str)
-            if version_str and version_tuple < _MIN_XREACH_VERSION:
-                min_str = ".".join(str(x) for x in _MIN_XREACH_VERSION)
-                return "warn", (
-                    f"xreach CLI 版本过旧（当前 {version_str}，需 >= {min_str}）。"
-                    f"旧版本无法读取长文推文（note_tweet）和 X Article。升级：\n"
-                    f"  npm install -g xreach-cli@latest"
-                )
-        except Exception:
-            pass  # version check failure is non-fatal; proceed to auth check
 
         try:
             r = subprocess.run(
-                [xreach, "auth", "check"], capture_output=True,
+                [bird, "check"], capture_output=True,
                 encoding="utf-8", errors="replace", timeout=10
             )
+            output = (r.stdout or "") + (r.stderr or "")
             if r.returncode == 0:
                 return "ok", "完整可用（读取、搜索推文，含长文/X Article）"
+            # bird check returns 1 when auth is missing
+            if "Missing credentials" in output or "missing" in output.lower():
+                return "warn", (
+                    "bird CLI 已安装但未配置认证。设置环境变量：\n"
+                    "  export AUTH_TOKEN=\"xxx\"\n"
+                    "  export CT0=\"yyy\"\n"
+                    "或运行：\n"
+                    "  agent-reach configure twitter-cookies \"auth_token=xxx; ct0=yyy\""
+                )
             return "warn", (
-                "xreach CLI 已安装但未配置 Cookie。运行：\n"
+                "bird CLI 已安装但认证检查失败。运行：\n"
                 "  agent-reach configure twitter-cookies \"auth_token=xxx; ct0=yyy\""
             )
         except Exception:
-            return "warn", "xreach CLI 已安装但连接失败"
+            return "warn", "bird CLI 已安装但连接失败"