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/.mcp.json

@@ -0,0 +1,8 @@
+{
+  "mcpServers": {
+    "probo": {
+      "type": "http",
+      "url": "${PROBO_BASE_URL}/mcp/v1"
+    }
+  }
+}