fix(twitter): migrate from deleted bird CLI to twitter-cli (#231)

steipete/bird repo has been deleted (404). Migrates to twitter-cli
(public-clis/twitter-cli, 2137 stars, Python, actively maintained).

Changes:
- twitter.py: check() now detects `twitter` binary, parses `twitter status` YAML
- cli.py: install via pipx/uv instead of npm, test via `twitter status`
- cli.py: remove bird/xfetch credential sync, use TWITTER_AUTH_TOKEN/CT0 env
- skill references: bird commands → twitter-cli commands
- tests: 5 new tests covering all check() paths

104 tests passing.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agent_reach/skill/SKILL.md

@@ -58,7 +58,7 @@ curl -s "https://r.jina.ai/URL"
 gh search repos "query" --sort stars --limit 10
 
 # Twitter 搜索
-bird search "query" -n 10
+twitter search "query" --limit 10
 
 # YouTube/B站字幕
 yt-dlp --write-sub --skip-download -o "/tmp/%(id)s" "URL"