feat: add new OpenSpec skills for change management and onboarding

- Created `openspec-ff-change` skill for fast-forward artifact creation.
- Introduced `openspec-new-change` skill for structured change creation.
- Developed `openspec-onboard` skill for guided onboarding through OpenSpec workflow.
- Added `openspec-sync-specs` skill for syncing delta specs to main specs.
- Implemented `openspec-verify-change` skill for verifying implementation against change artifacts.
- Updated `.gitignore` to exclude OpenSpec generated files.
- Added `skills-lock.json` to manage skill dependencies.

.agents/skills/tailwindcss/references/transform-rotate.md

@@ -0,0 +1,70 @@
+---
+name: transform-rotate
+description: Rotating elements in 2D and 3D space with degree values and custom rotations
+---
+
+# Rotate
+
+Utilities for rotating elements.
+
+## Usage
+
+### 2D rotation
+
+Use `rotate-<number>` to rotate by degrees:
+
+```html
+<div class="rotate-45">45 degrees</div>
+<div class="rotate-90">90 degrees</div>
+<div class="-rotate-45">-45 degrees (counterclockwise)</div>
+```
+
+### 3D rotation
+
+Use `rotate-x-<number>`, `rotate-y-<number>`, `rotate-z-<number>` for 3D rotation:
+
+```html
+<div class="rotate-x-50 rotate-z-45">3D rotation</div>
+<div class="rotate-y-25 rotate-z-30">Combined 3D rotation</div>
+```
+
+### Common rotations
+
+```html
+<div class="rotate-90">Quarter turn</div>
+<div class="rotate-180">Half turn</div>
+<div class="rotate-270">Three-quarter turn</div>
+```
+
+### Custom values
+
+Use arbitrary values for custom rotations:
+
+```html
+<div class="rotate-[3.142rad]">Custom radian rotation</div>
+<div class="rotate-[45deg]">Explicit degree rotation</div>
+```
+
+### Removing rotation
+
+Use `rotate-none` to remove rotation:
+
+```html
+<div class="rotate-45 md:rotate-none">Rotated on mobile only</div>
+```
+
+## Key Points
+
+- `rotate-*` rotates in 2D plane (around z-axis)
+- `rotate-x-*` rotates around x-axis (3D)
+- `rotate-y-*` rotates around y-axis (3D)
+- `rotate-z-*` rotates around z-axis (3D, same as `rotate-*`)
+- Negative values rotate counterclockwise: `-rotate-45`
+- Common values: `45`, `90`, `180`, `270` degrees
+- Can combine multiple axes: `rotate-x-50 rotate-y-30 rotate-z-45`
+- Use `rotate-none` to remove all rotations
+
+<!--
+Source references:
+- https://tailwindcss.com/docs/rotate
+-->