add new skill to copilot-instructions (#3029)

Author: sawka

.github/copilot-instructions.md

@@ -18,6 +18,7 @@ This project uses a set of "skill" guides — focused how-to documents for commo
 | [context-menu](./.kilocode/skills/context-menu/SKILL.md) | Guide for creating and displaying context menus in Wave Terminal. Use when implementing right-click menus, adding context menu items, creating submenus, or handling menu interactions with checkboxes and separators. |
 | [create-view](./.kilocode/skills/create-view/SKILL.md) | Guide for implementing a new view type in Wave Terminal. Use when creating a new view component, implementing the ViewModel interface, registering a new view type in BlockRegistry, or adding a new content type to display within blocks. |
 | [electron-api](./.kilocode/skills/electron-api/SKILL.md) | Guide for adding new Electron APIs to Wave Terminal. Use when implementing new frontend-to-electron communications via preload/IPC. |
+| [waveenv](./.kilocode/skills/waveenv/SKILL.md) | Guide for creating WaveEnv narrowings in Wave Terminal. Use when writing a named subset type of WaveEnv for a component tree, documenting environmental dependencies, or enabling mock environments for preview/test server usage. |
 | [wps-events](./.kilocode/skills/wps-events/SKILL.md) | Guide for working with Wave Terminal's WPS (Wave PubSub) event system. Use when implementing new event types, publishing events, subscribing to events, or adding asynchronous communication between components. |
 
 > **How skills work:** Each skill is a self-contained guide covering the exact files to edit, patterns to follow, and steps to take for a specific type of task in this codebase. If your task matches a skill's description, open that SKILL.md and treat it as your primary reference for the implementation.