feat: Add M3 Divider for Vue and React

[cmath10]

Summary

Add Divider from Material 3 to both m3-vue and m3-react.

Problem

Divider is in the M3 catalog and absent from both workspaces.

Scope

• Implement component API and rendering in m3-vue.
• Implement equivalent API and behavior in m3-react.
• Add Storybook docs and examples for both workspaces.
• Add tests and ensure parity between frameworks.

Acceptance Criteria

1. Component is exported from both package entrypoints.
2. Storybook has Docs and practical usage stories in both workspaces.
3. ARIA semantics are documented in MDX.
4. Lint, tests, and typecheck are green.

Reference

• https://m3.material.io/components/divider/overview