Add comprehensive skills, agents, commands collection

- Added 44 external skills from obra/superpowers, ui-ux-pro-max-skill, claude-codex-settings
- Added 8 autonomous agents (commit-creator, pr-creator, pr-reviewer, etc.)
- Added 23 slash commands for Git/GitHub, setup, and plugin development
- Added hooks for code formatting, notifications, and validation
- Added MCP configurations for Azure, GCloud, Supabase, MongoDB, etc.
- Added awesome-openclaw-skills registry (3,002 skills referenced)
- Updated comprehensive README with full documentation

Sources:
- github.com/obra/superpowers (14 skills)
- github.com/nextlevelbuilder/ui-ux-pro-max-skill (1 skill)
- github.com/fcakyon/claude-codex-settings (29 skills, 8 agents, 23 commands)
- github.com/VoltAgent/awesome-openclaw-skills (registry)
- skills.sh (reference)
- buildwithclaude.com (reference)

skills/external/plugin-dev-mcp-integration/examples/sse-server.json

@@ -0,0 +1,19 @@
+{
+  "_comment": "Example SSE MCP server configuration for hosted cloud services",
+  "asana": {
+    "type": "sse",
+    "url": "https://mcp.asana.com/sse"
+  },
+  "github": {
+    "type": "sse",
+    "url": "https://mcp.github.com/sse"
+  },
+  "custom-service": {
+    "type": "sse",
+    "url": "https://mcp.example.com/sse",
+    "headers": {
+      "X-API-Version": "v1",
+      "X-Client-ID": "${CLIENT_ID}"
+    }
+  }
+}