Trim down the agent skills, let agents auto-discover

[mattiasgeniar]

Why

The agent skill was bloating context windows by inlining every CLI command with full examples (~306 lines), duplicating what the reference files and the CLI's own --help already provide. CLI-wrapping skills should teach agents to discover commands, not enumerate them.

What changed

• Rewrote SKILL.md to use progressive disclosure: auth, discovery instructions (ohdear list / --help), output format, and pointers to reference files. 306 lines down to 65.
• Rebuilt commands.md as a category index with key commands per group instead of exhaustive per-command tables. Added 39 previously missing commands across 6 new categories (DNS blocklists, port scanning, sitemap, recurring maintenance, status page templates, managed teams).
• Fixed incorrect "All commands output JSON" claim everywhere (SKILL.md, commands.md, README.md) — default is human-readable text, --json is opt-in.
• Updated stale metadata (version 5.0.0 to 5.1.3) and example dates.