Add installable agent skill for skills.sh

[andreagrandi]

Summary

Ships a canonical, public logbasset agent skill at skills/logbasset/SKILL.md, installable via skills.sh (npx skills add andreagrandi/logbasset). The goal is to encourage users to install the skill alongside the binary so their coding agent knows when and how to reach for the CLI.

Design

The skill is intentionally a thin pointer, not a copy of the docs:

• It does not restate commands or flags. Its runtime workflow is: check the binary is on PATH, then run logbasset context (authoritative reference) and logbasset schema <command> (exact flags) before composing a query.
• Because nothing in it is flag- or command-specific, a CLI change can never make it stale, and it stays out of the existing per-flag doc-sync checklist.
• Written in agent-neutral voice (no assumptions about a specific agent), since skills.sh installs to many agents (Claude Code, Codex, Cursor, and others).
• Includes a binary-presence preflight — the one thing the skill must own, since a missing binary can't be discovered by running logbasset context.

Changes

• skills/logbasset/SKILL.md — new skill (pure pointer, delegates to logbasset context / logbasset schema).
• README.md — "Use with AI Coding Agents" section with the install command.
• CHANGELOG.md — [Unreleased] entry.
• AGENTS.md — note exempting the skill from the per-flag doc-sync checklist so contributors don't reintroduce drift.
• .gitignore — anchor the logbasset binary pattern to the repo root (/logbasset) so it no longer matches the skills/logbasset/ directory. The root and bin/ binaries remain ignored.

Validation

npx skills add . --list discovers exactly one skill (logbasset) with the expected description, confirming the SKILL.md frontmatter is well-formed.