feat(kyberforge): add agent-audit skill (closes #11)

## Why

agent-author produces paired agent definition files (Claude Code .md +
Copilot .agent.md) but had no companion audit skill to validate them.
agent-audit fills that gap, giving the same structured PASS/FAIL report
that skill-audit provides for SKILL.md files.

## Implementation Notes

- validate.sh uses scope detection (walk up for plugin.json / .git) to
  locate the counterpart file and determine whether plugin-silently-ignored
  fields (hooks, mcpServers, permissionMode) should be flagged
- CC-only and silently-ignored field lists are read from
  references/field-inventory.md at runtime rather than hardcoded —
  provenance back to the research corpus; see ADR-0019
- Single-file invocation (pass either file, counterpart derived) chosen
  over directory or name+root — see ADR-0018
- 12 bats tests cover provider detection, scope detection, all FAIL paths,
  and clean-pair pass

## Impact

- kyberforge bumped to v1.1.2
- agent-author close step should be updated to reference agent-audit (#11)
- Provenance/sources chain check deferred to #60

ADR: docs/adr/0018-agent-audit-single-file-invocation.md
ADR: docs/adr/0019-agent-audit-field-inventory-reference.md
Refs: #11
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0147vXtL5sP6vorDdqXGJJU9

plugins/kyberforge/skills/agent-audit/references/README.md

@@ -0,0 +1,10 @@
+# references/
+
+Additional documentation agents load on demand.
+
+## Files
+
+| File | Purpose |
+|------|---------|
+| `field-inventory.md` | Canonical list of valid CC and Copilot agent definition fields. Load when the script needs authoritative field lists for structural validation. |
+| `sources.md` | Research provenance records for skill content. Load only when tracing the origin of a specific rule or field constraint. |

plugins/kyberforge/skills/agent-audit/references/field-inventory.md

@@ -0,0 +1,24 @@
+---
+source_keys:
+  - context7-websites-code-claude
+  - claude-code-plugins-docs
+  - claude-code-subagents-docs
+  - context7-github-en-copilot
+  - github-custom-agents-configuration
+---
+
+## claude-code-fields
+
+name description tools disallowedTools model effort maxTurns permissionMode skills mcpServers hooks memory background isolation color initialPrompt
+
+## claude-code-only-fields
+
+maxTurns isolation memory permissionMode effort hooks mcpServers disallowedTools skills initialPrompt color background
+
+## plugin-silently-ignored-fields
+
+hooks mcpServers permissionMode
+
+## copilot-fields
+
+name description tools target model disable-model-invocation user-invocable mcp-servers metadata

plugins/kyberforge/skills/agent-audit/references/sources.md

@@ -0,0 +1,90 @@
+---
+source_keys:
+  - context7-websites-code-claude
+  - claude-code-plugins-docs
+  - claude-code-subagents-docs
+  - context7-github-en-copilot
+  - github-custom-agents-configuration
+---
+
+# Sources
+
+## context7-websites-code-claude
+
+- **URL:** context7:/websites/code_claude
+- **Research doc:** plugins/kyberforge/docs/research/docs/claude-code-plugins/sources.md
+- **Description:** Official Claude Code documentation site indexed by Context7 — plugin manifest schema, subagent definition types, marketplace JSON format, agent markdown file format
+- **Contributing files:** SKILL.md, references/field-inventory.md
+- **Status:** `extracted`
+
+## claude-code-plugins-docs
+
+- **URL:** https://code.claude.com/docs/en/plugins
+- **Research doc:** plugins/kyberforge/docs/research/docs/claude-code-plugins/sources.md
+- **Description:** Official Claude Code plugin authoring guide — plugin structure, manifest fields, loading methods, skill namespacing, agent activation, marketplace submission
+- **Contributing files:** SKILL.md, references/field-inventory.md
+- **Status:** `extracted`
+
+## claude-code-subagents-docs
+
+- **URL:** https://code.claude.com/docs/en/sub-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/claude-code-plugins/sources.md
+- **Description:** Official Claude Code subagent reference — definition format, all frontmatter fields, scope priority, built-in agents, CLI flags, environment variables, known limitations
+- **Contributing files:** SKILL.md, references/field-inventory.md
+- **Status:** `extracted`
+
+## context7-github-en-copilot
+
+- **URL:** context7:/websites/github_en_copilot
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Official GitHub Copilot documentation indexed by Context7; covers CLI plugins, custom agents, SDK, and marketplace
+- **Contributing files:** SKILL.md, references/field-inventory.md
+- **Status:** `extracted`
+
+## github-custom-agents-configuration
+
+- **URL:** https://docs.github.com/en/copilot/reference/custom-agents-configuration
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Reference for cloud and IDE custom agent definition format — frontmatter fields, tool aliases, MCP server config, secrets interpolation, scoping hierarchy
+- **Contributing files:** SKILL.md, references/field-inventory.md
+- **Status:** `extracted`
+
+## github-cli-plugin-reference
+
+- **URL:** https://docs.github.com/en/copilot/reference/copilot-cli-reference/cli-plugin-reference
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Full CLI plugin reference — plugin.json schema, marketplace.json schema, all CLI commands and flags, install specification formats, loading precedence, env vars, LSP config
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-plugins-creating
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-creating
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for creating Copilot CLI plugins — plugin structure, agent and skill authoring, hooks format, MCP config, development lifecycle
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-plugins-finding-installing
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-finding-installing
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** User-facing guide to discovering and installing CLI plugins — marketplace browsing commands, install/update/uninstall workflow
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-plugins-marketplace
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-marketplace
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for creating and publishing a plugin marketplace — marketplace.json structure, hosting options, registration commands
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-sdk-custom-agents
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-sdk/features/custom-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** SDK custom agent API — CustomAgentConfig fields in all five languages, session config, sub-agent lifecycle events, tool scoping, permission handling
+- **Contributing files:** (none)
+- **Status:** `extracted`