Add @probo/skills multi-agent compliance package

Ship compliance skills and agent plugin wiring for Claude Code,
Codex, OpenCode, and Cursor via Probo MCP (OAuth 2.0). Includes
access-review and missing-signatures workflows, repo-root Git
marketplaces, validation, and npm release CI.

Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>

packages/skills/README.md

@@ -0,0 +1,98 @@
+# @probo/skills
+
+Multi-agent compliance skills for open-source GRC workflows. Ships Agent
+Skills–compatible instructions and wires agents to the [Probo MCP
+API](https://github.com/getprobo/probo/tree/main/pkg/server/api/mcp/v1) via
+OAuth 2.0.
+
+**Supported agents:** Claude Code, Codex, OpenCode, Cursor (MCP + skills).
+
+Marketplace catalogs: `.claude-plugin/marketplace.json` at the repo root or
+under `packages/skills/` (Claude Code), `.agents/plugins/marketplace.json` at
+the repo root or under `packages/skills/` (Codex). See
+[COMPATIBILITY.md](./COMPATIBILITY.md).
+
+## Install
+
+### From GitHub or npm
+
+**From GitHub** (repo-root catalog at `.claude-plugin/marketplace.json`):
+
+```bash
+claude plugin marketplace add getprobo/probo
+# or, from a local clone:
+claude plugin marketplace add .
+claude plugin install probo@probo
+```
+
+**From the package directory** (catalog at
+`packages/skills/.claude-plugin/marketplace.json`, resolves `@probo/skills`
+from npm):
+
+```bash
+claude plugin marketplace add ./packages/skills/.claude-plugin
+claude plugin install probo@probo
+```
+
+When consuming the published package, the package-level marketplace entry
+resolves `@probo/skills` from npm (see
+`packages/skills/.claude-plugin/marketplace.json`).
+
+### Configure Probo MCP
+
+Set your Probo instance URL before starting Claude Code:
+
+```bash
+export PROBO_BASE_URL="https://your-probo-instance.example.com"
+```
+
+The plugin `.mcp.json` connects to `${PROBO_BASE_URL}/mcp/v1`. Probo MCP
+authenticates with **OAuth 2.0** — no API token or bearer header is required in
+the plugin config. On first use, sign in from Claude Code:
+
+```text
+/mcp
+```
+
+Or from your shell:
+
+```bash
+claude mcp login probo
+```
+
+Claude Code discovers Probo's authorization server via
+`/.well-known/oauth-protected-resource` and stores tokens securely.
+
+### Local development
+
+```bash
+claude --plugin-dir ./packages/skills
+```
+
+## What's included
+
+| Component | Location | Purpose |
+| --- | --- | --- |
+| MCP | `.mcp.json` | Probo API connection |
+| Skills | `skills/` | Compliance workflows |
+| Commands | `commands/` | `access-review`, `missing-signatures` — semi-auto workflows |
+| Agents | `agents/` | Reserved |
+| Hooks | `hooks/` | Reserved |
+
+Skills: `/probo:<skill-name>` (e.g. `/probo:open-source-compliance`, `/probo:missing-signatures`).
+
+Commands: `/probo:<command-name>` (e.g. `/probo:access-review`, `/probo:missing-signatures`).
+
+## Adding content
+
+See [`contrib/claude/skills.md`](../../contrib/claude/skills.md).
+
+```bash
+npm --workspace @probo/skills run validate
+claude --plugin-dir ./packages/skills
+```
+
+## Release
+
+Published to npm as `@probo/skills`. See
+[`contrib/claude/release/skills.md`](../../contrib/claude/release/skills.md).