[nixos-configs-7hd] Add parallel_beads skill for orchestrating bead processing

- Add skills/ directory for local Claude skills
- Create parallel_beads.md skill that orchestrates:
  - Phase 1: Multi-select bead selection from bd ready
  - Phase 2: Parallel subagents for implementation (worktree, implement, commit, PR)
  - Phase 3: Parallel review subagents
  - Phase 4: Cleanup and summary
- Update default.nix to install local skills alongside humanlayer plugins
- Support both gh (GitHub) and tea (Gitea/Forgejo) based on origin URL

home/roles/development/default.nix

@@ -85,11 +85,20 @@ in
         fi
       done
 
+      # Copy local skills from this repo
+      for file in ${./skills}/*.md; do
+        if [ -f "$file" ]; then
+          filename=$(basename "$file" .md)
+          dest="$HOME/.claude/commands/humanlayer:''${filename}.md"
+          cp "$file" "$dest"
+        fi
+      done
+
       $DRY_RUN_CMD echo "Claude Code humanlayer commands and agents installed successfully${
         if cfg.allowArbitraryClaudeCodeModelSelection
         then " (model specifications preserved)"
         else " (model selection removed)"
-      }"
+      } + local skills"
     '';
 
     # Set up beads Claude Code integration (hooks for SessionStart/PreCompact)