feat: Complete fleet — 94 skills across 10+ domains

Pulled ALL skills from 15 source repositories:
- anthropics/skills: 16 (docs, design, MCP, testing)
- obra/superpowers: 14 (TDD, debugging, agents, planning)
- coreyhaines31/marketingskills: 25 (marketing, CRO, SEO, growth)
- better-auth/skills: 5 (auth patterns)
- vercel-labs/agent-skills: 5 (React, design, Vercel)
- antfu/skills: 16 (Vue, Vite, Vitest, pnpm, Turborepo)
- Plus 13 individual skills from various repos

Mosaic Stack is not limited to coding — the Orchestrator and
subagents serve coding, business, design, marketing, writing,
logistics, analysis, and more.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/vitest/SKILL.md

@@ -0,0 +1,52 @@
+---
+name: vitest
+description: Vitest fast unit testing framework powered by Vite with Jest-compatible API. Use when writing tests, mocking, configuring coverage, or working with test filtering and fixtures.
+metadata:
+  author: Anthony Fu
+  version: "2026.1.28"
+  source: Generated from https://github.com/vitest-dev/vitest, scripts located at https://github.com/antfu/skills
+---
+
+Vitest is a next-generation testing framework powered by Vite. It provides a Jest-compatible API with native ESM, TypeScript, and JSX support out of the box. Vitest shares the same config, transformers, resolvers, and plugins with your Vite app.
+
+**Key Features:**
+- Vite-native: Uses Vite's transformation pipeline for fast HMR-like test updates
+- Jest-compatible: Drop-in replacement for most Jest test suites
+- Smart watch mode: Only reruns affected tests based on module graph
+- Native ESM, TypeScript, JSX support without configuration
+- Multi-threaded workers for parallel test execution
+- Built-in coverage via V8 or Istanbul
+- Snapshot testing, mocking, and spy utilities
+
+> The skill is based on Vitest 3.x, generated at 2026-01-28.
+
+## Core
+
+| Topic | Description | Reference |
+|-------|-------------|-----------|
+| Configuration | Vitest and Vite config integration, defineConfig usage | [core-config](references/core-config.md) |
+| CLI | Command line interface, commands and options | [core-cli](references/core-cli.md) |
+| Test API | test/it function, modifiers like skip, only, concurrent | [core-test-api](references/core-test-api.md) |
+| Describe API | describe/suite for grouping tests and nested suites | [core-describe](references/core-describe.md) |
+| Expect API | Assertions with toBe, toEqual, matchers and asymmetric matchers | [core-expect](references/core-expect.md) |
+| Hooks | beforeEach, afterEach, beforeAll, afterAll, aroundEach | [core-hooks](references/core-hooks.md) |
+
+## Features
+
+| Topic | Description | Reference |
+|-------|-------------|-----------|
+| Mocking | Mock functions, modules, timers, dates with vi utilities | [features-mocking](references/features-mocking.md) |
+| Snapshots | Snapshot testing with toMatchSnapshot and inline snapshots | [features-snapshots](references/features-snapshots.md) |
+| Coverage | Code coverage with V8 or Istanbul providers | [features-coverage](references/features-coverage.md) |
+| Test Context | Test fixtures, context.expect, test.extend for custom fixtures | [features-context](references/features-context.md) |
+| Concurrency | Concurrent tests, parallel execution, sharding | [features-concurrency](references/features-concurrency.md) |
+| Filtering | Filter tests by name, file patterns, tags | [features-filtering](references/features-filtering.md) |
+
+## Advanced
+
+| Topic | Description | Reference |
+|-------|-------------|-----------|
+| Vi Utilities | vi helper: mock, spyOn, fake timers, hoisted, waitFor | [advanced-vi](references/advanced-vi.md) |
+| Environments | Test environments: node, jsdom, happy-dom, custom | [advanced-environments](references/advanced-environments.md) |
+| Type Testing | Type-level testing with expectTypeOf and assertType | [advanced-type-testing](references/advanced-type-testing.md) |
+| Projects | Multi-project workspaces, different configs per project | [advanced-projects](references/advanced-projects.md) |