feat(ingest): downstream web-artifacts-builder for rapid prototyping

[harshsinghmp]

Classification

actionable-feature

Context & Rationale

anthropics/skills/web-artifacts-builder generates self-contained, interactive single-file web artifacts (React, Tailwind CSS, Lucide icons) in one deterministic pass for rapid UI prototyping.

Scope & Ingestion Plan

1. Ingest upstream from https://github.com/anthropics/skills/tree/main/skills/web-artifacts-builder.
2. Place into skills/creative/web-artifacts-builder.
3. Register in skills.manifest.json and catalog under Creative, UI/UX & Visuals.

Verification Criteria

• skills/creative/web-artifacts-builder/SKILL.md exists and passes manifest schema validation.
• Registered in skills.manifest.json.
• Validated via bun test.