When installed as a plugin, /plan triggers Claude Code's built-in plan
mode instead of the plugin's plan skill. Updated all 4 README files
(EN, zh-CN, zh-TW, ja-JP) to show the plugin-namespaced form with a
comment noting the shorter form works for manual installs.
Also fixes markdownlint MD012 violation in chief-of-staff.md (trailing
double blank line from #280 merge).
Fixes#297
New articles:
- the-security-guide.md: "The Shorthand Guide to Securing Your Agent" (595 lines)
Attack vectors, sandboxing, sanitization, OWASP Top 10, observability
- the-openclaw-guide.md: "The Hidden Danger of OpenClaw" (470 lines)
Security analysis of OpenClaw, MiniClaw thesis, industry evidence
External link sanitization (22 files across EN, zh-CN, zh-TW, ja-JP, .cursor):
- Removed third-party GitHub links from skills and guides
- Replaced with inline descriptions to prevent transitive prompt injection
- Kept official org links (Anthropic, Google, Supabase, Mixedbread)