feat: Add installation tool, Claude.ai export, and skill standardization (#1)

## Summary

- Add portable installation tool (`install.sh`) for cross-machine setup
- Add Claude.ai export files with proper YAML frontmatter
- Add multi-agent-guide v2.0 with consolidated framework template
- Rename `00-claude-code-setting` → `00-our-settings-audit` (avoid reserved word)
- Add YAML frontmatter to 25+ SKILL.md files for Claude Desktop compatibility

## Commits Included

- `93f604a` feat: Add portable installation tool for cross-machine setup
- `9b84104` feat: Add Claude.ai export for portable skill installation
- `f7ab973` fix: Add YAML frontmatter to Claude.ai export files
- `3fed49a` feat(multi-agent-guide): Add v2.0 with consolidated framework
- `3be26ef` refactor: Rename settings-audit skill and add YAML frontmatter

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

custom-skills/91-multi-agent-guide/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "multi-agent-guide",
-  "version": "1.0.0",
-  "description": "Multi-agent collaboration framework for complex projects. Sets up agent hierarchies, ownership rules, guardrails, handoff protocols, and CI/CD integration for Claude, Gemini, Codex, and Human agents working together.",
+  "version": "2.0.0",
+  "description": "Multi-agent collaboration framework for complex projects. Sets up agent hierarchies, ownership rules, guardrails, handoff protocols, and CI/CD integration for Claude, Gemini, Codex, and Human agents working together. v2.0 includes consolidated MULTI_AGENT_FRAMEWORK.md template and quick-setup command.",
   "author": {
     "name": "OurDigital",
     "email": "ourdigital@example.com"
@@ -12,7 +12,21 @@
     "guardrails",
     "ownership",
     "ci-cd",
-    "project-management"
+    "project-management",
+    "framework",
+    "claude",
+    "gemini",
+    "codex"
   ],
-  "license": "MIT"
+  "license": "MIT",
+  "commands": [
+    {
+      "name": "multi-agent-setup",
+      "description": "Quick setup for multi-agent collaboration"
+    },
+    {
+      "name": "setup-agents",
+      "description": "Full interactive multi-agent setup"
+    }
+  ]
 }