Sanitize for open-source release

- Replace internal tenant name yitanger.feishu.cn with your-tenant.feishu.cn
- Replace real wiki token with placeholder WikiNodeTokenExample
- Parameterize tenant via FEISHU_TENANT env var in feishu-to-md.mjs
- Expand .gitignore to cover cookies, auth artifacts, IDE files

.gitignore

@@ -1,2 +1,22 @@
+# Dependencies
 node_modules
+
+# Output
 output
+
+# Cookies / sessions (auto-generated by scraper)
+cookies.json
+feishu-cookies.json
+feishu-wiki-cookies.json
+*-cookies.json
+
+# Auth artifacts
+feishu-auth-qr.png
+
+# Local config / IDE
+.claude/
+.debug/
+.DS_Store
+
+# Bundled browsers (pkg build output)
+browsers/