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/effects-transition-animation.md

@@ -0,0 +1,80 @@
+---
+name: effects-transition-animation
+description: CSS transitions, animation keyframes, and reduced motion support
+---
+
+# Transition & Animation
+
+Utilities for CSS transitions and animations.
+
+## Usage
+
+### Transition property
+
+```html
+<button class="transition hover:bg-blue-600">Transitions common properties</button>
+<button class="transition-all hover:scale-110">All properties</button>
+<button class="transition-colors hover:bg-indigo-500">Colors only</button>
+<button class="transition-opacity hover:opacity-75">Opacity only</button>
+<button class="transition-transform hover:translate-y-1">Transform only</button>
+<button class="transition-none">No transition</button>
+```
+
+### Transition duration and delay
+
+```html
+<button class="transition duration-150">150ms (default)</button>
+<button class="transition duration-300">300ms</button>
+<button class="transition duration-500">500ms</button>
+<button class="transition delay-150">Delay 150ms</button>
+<button class="transition duration-300 delay-100">Both</button>
+```
+
+### Transition timing
+
+```html
+<button class="transition ease-linear">Linear</button>
+<button class="transition ease-in">Ease in</button>
+<button class="transition ease-out">Ease out</button>
+<button class="transition ease-in-out">Ease in-out (default)</button>
+<button class="transition ease-[cubic-bezier(0.4,0,0.2,1)]">Arbitrary</button>
+```
+
+### Animation keyframes
+
+```html
+<div class="animate-spin">Spinning</div>
+<div class="animate-ping">Ping effect</div>
+<div class="animate-pulse">Pulse</div>
+<div class="animate-bounce">Bounce</div>
+```
+
+Built-in: `animate-spin`, `animate-ping`, `animate-pulse`, `animate-bounce`. Use `@keyframes` in custom CSS for more.
+
+### Reduced motion
+
+```html
+<button class="transition hover:-translate-y-1 motion-reduce:transition-none motion-reduce:hover:translate-y-0">
+  Respects prefers-reduced-motion
+</button>
+<div class="animate-spin motion-reduce:animate-none">Spinner hidden when reduced motion</div>
+```
+
+Use `motion-reduce:` to disable or simplify animations when user prefers reduced motion.
+
+## Key Points
+
+- Transition: `transition`, `transition-all`, `transition-colors`, `transition-opacity`, `transition-transform`
+- Duration: `duration-{75,100,150,200,300,500,700,1000}`
+- Delay: `delay-{75,100,150,200,300,500,700,1000}`
+- Timing: `ease-{linear,in,in-out,out}`
+- Animation: `animate-spin`, `animate-ping`, `animate-pulse`, `animate-bounce`
+- Always consider `motion-reduce:` for accessibility
+
+<!--
+Source references:
+- https://tailwindcss.com/docs/transition-property
+- https://tailwindcss.com/docs/transition-duration
+- https://tailwindcss.com/docs/transition-timing-function
+- https://tailwindcss.com/docs/animation
+-->