agent-config — surface a Culture agent's config in one view

guildmaster is the mesh's skills supplier and owns the inventory surfaces: "what kit + config does this agent have?" This skill answers exactly that for a single agent, showing the three artifacts that together define it:

1. System-prompt file (CLAUDE.md / AGENTS.md / GEMINI.md) — the prompt-side guidance for the agent's backend. The script detects which file is present from a backend-fingerprint registry.
2. culture.yaml — the runtime-side config (agents: list with suffix, backend, model, system_prompt, channels, tags, acp_command, extras). Lives parallel to the prompt file at the project root.
3. .claude/skills/*/SKILL.md — the per-project skills the agent can invoke, one line each (name + truncated description).

This is the inventory half of the steward → guildmaster split (issue #12): it reports the config, it does not interpret drift or judge alignment. The relationship graph and the "is this agent aligned?" judgment stay with steward overview / steward doctor.

When to use

• Before guild teach / guild onboard — see an agent's current kit + config.
• When an operator asks "show me agent <name>" or "what does <agent> run".
• Read it, don't guess — before answering a question about what an agent does.

How to run

One script, two ways to call it (or just run guild show, which wraps it):

# Path mode — point at any directory with a prompt file + culture.yaml
.claude/skills/agent-config/scripts/show.sh ../culture

# Suffix mode — resolve a registered agent suffix via the Culture server's
# manifest (location set by culture_server_yaml in skills.local.yaml)
.claude/skills/agent-config/scripts/show.sh daria

Output is three sections: the detected system-prompt file, culture.yaml (or (missing)), and a one-line summary per local skill (name + description, truncated to 120 chars).

What to look at in culture.yaml

Field	Why it matters
suffix	Identifies the agent on the mesh.
backend	One of claude / codex / copilot / acp. The all-backends rule means a feature in one must land in all four.
model	Drift here changes behavior silently.
system_prompt	Should not contradict the prompt file.
channels	Where the agent listens.
tags, extras, acp_command	Backend-specific.

Notes

• Read-only. The script never edits agent files. It reports; it does not flag or fix drift — that judgment is steward's lane.
• Backend-aware. Prompt-file detection comes from data/backend-fingerprints.yaml (the prompt: mapping), falling back to the built-in (CLAUDE.md AGENTS.md GEMINI.md) list if the registry is absent.
• Per-machine config. Suffix mode reads culture_server_yaml from .claude/skills.local.yaml (git-ignored), falling back to .claude/skills.local.yaml.example.
• Vendored from steward (agent-config). guildmaster owns this copy and may diverge; re-sync from steward's canonical copy when it changes. Divergences: the SKILL.md is reframed for guildmaster's inventory role and adds type: command for the culture backend's skill loader.