Add Skills Over MCP Interest Group role and users (#56)

* Add Skills Over MCP Interest Group and experimental-ext-skills repo

- Add SKILLS_OVER_MCP_IG role under interest-groups (GitHub team only)
- Add repo access for experimental-ext-skills per SEP-2133 governance:
  - core-maintainers: admin (oversight)
  - moderators: triage
  - skills-over-mcp-ig: admin (day-to-day governance)
- Add IG membership for: cliffhall, erain, JAORMX, kaxil, keithagroves,
  olaservo, pederhp, SamMorrowDrums, TeamSparkAI

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add SKILLS_OVER_MCP_IG role to user membership

* Fix alphabetical sorting of users

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Paul Carleton <paulcarletonjr@gmail.com>

src/config/roles.ts

@@ -307,6 +307,12 @@ export const ROLES: readonly Role[] = [
     // No GitHub role yet
     discord: { role: 'gateways interest group (synced)' },
   },
+  {
+    id: ROLE_IDS.SKILLS_OVER_MCP_IG,
+    description: 'Skills Over MCP Interest Group',
+    github: { team: 'skills-over-mcp-ig', parent: ROLE_IDS.INTEREST_GROUPS },
+    // No Discord role yet
+  },
 
   // ===================
   // WG/IG Facilitators (Discord only)