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-skew.md

@@ -0,0 +1,62 @@
+---
+name: transform-skew
+description: Skewing elements on x and y axes with degree values
+---
+
+# Skew
+
+Utilities for skewing (distorting) elements.
+
+## Usage
+
+### Skewing both axes
+
+Use `skew-<number>` to skew on both axes:
+
+```html
+<div class="skew-3">Slight skew</div>
+<div class="skew-6">Moderate skew</div>
+<div class="skew-12">Strong skew</div>
+```
+
+### Axis-specific skewing
+
+Use `skew-x-<number>` or `skew-y-<number>` to skew on one axis:
+
+```html
+<div class="skew-x-12">Skewed horizontally</div>
+<div class="skew-y-6">Skewed vertically</div>
+```
+
+### Negative skewing
+
+Use negative values for opposite direction:
+
+```html
+<div class="-skew-3">Negative skew</div>
+<div class="-skew-x-12">Negative x-axis skew</div>
+```
+
+### Custom values
+
+Use arbitrary values for custom skew:
+
+```html
+<div class="skew-[3.142rad]">Custom radian skew</div>
+<div class="skew-x-[15deg]">Custom degree skew</div>
+```
+
+## Key Points
+
+- `skew-*` skews on both x and y axes
+- `skew-x-*` skews horizontally only
+- `skew-y-*` skews vertically only
+- Values are in degrees: `skew-3` = 3 degrees
+- Negative values skew in opposite direction
+- Common values: `3`, `6`, `12` degrees for subtle effects
+- Use sparingly - excessive skewing can make text hard to read
+
+<!--
+Source references:
+- https://tailwindcss.com/docs/skew
+-->