Enhancement: Plugin system — clearer plugin discovery and installation

[Delqhi]

Enhancement: Plugin System — clearer plugin discovery and installation

Inspired by

Oh-My-Pi plugin install, Claude Code skills marketplace

What it does

Clearer distinction between skills (instruction sets) and plugins (executable extensions). One-command install.

Proposed CLI

sin-code plugin install <name>     # install a plugin
sin-code plugin list               # list installed plugins
sin-code plugin search <query>     # search available plugins
sin-code plugin remove <name>      # remove a plugin
sin-code plugin update [name]      # update plugin(s)

Current state

• sin-code skill install — distributes skill artifacts to agent families
• sin-code mcp discover/add — discovers MCP servers
• 42 bundled skills, 15 MCP servers, 306 MCP tools
• Missing: unified plugin command that bridges skills + MCP

Implementation approach

1. plugin = skill + MCP server + slash commands bundled together
2. plugin install = download skill + register MCP server + install slash commands
3. Plugin registry: GitHub repos with sin-plugin.json manifest
4. sin-code plugin search queries the registry

Priority: Low

Effort: Medium