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/tsdown/references/option-tree-shaking.md

@@ -0,0 +1,335 @@
+# Tree Shaking
+
+Remove unused code from bundles.
+
+## Overview
+
+Tree shaking eliminates dead code (unused exports) from your final bundle, reducing size and improving performance.
+
+**Default:** Enabled
+
+## Basic Usage
+
+### CLI
+
+```bash
+# Tree shaking enabled (default)
+tsdown
+
+# Disable tree shaking
+tsdown --no-treeshake
+```
+
+### Config File
+
+```ts
+export default defineConfig({
+  entry: ['src/index.ts'],
+  treeshake: true,  // Default
+})
+```
+
+## How It Works
+
+### With Tree Shaking
+
+**Source:**
+```ts
+// src/util.ts
+export function unused() {
+  console.log("I'm unused")
+}
+
+export function hello(x: number) {
+  console.log('Hello World', x)
+}
+
+// src/index.ts
+import { hello } from './util'
+hello(1)
+```
+
+**Output:**
+```js
+// dist/index.mjs
+function hello(x) {
+  console.log('Hello World', x)
+}
+hello(1)
+```
+
+`unused()` function is removed because it's never imported.
+
+### Without Tree Shaking
+
+**Output:**
+```js
+// dist/index.mjs
+function unused() {
+  console.log("I'm unused")
+}
+
+function hello(x) {
+  console.log('Hello World', x)
+}
+hello(1)
+```
+
+All code is included, even if unused.
+
+## Advanced Configuration
+
+### Enable (Default)
+
+```ts
+export default defineConfig({
+  treeshake: true,
+})
+```
+
+Uses Rolldown's default tree shaking.
+
+### Custom Options
+
+```ts
+export default defineConfig({
+  treeshake: {
+    moduleSideEffects: false,
+    propertyReadSideEffects: false,
+    unknownGlobalSideEffects: false,
+  },
+})
+```
+
+See [Rolldown docs](https://rolldown.rs/reference/config-options#treeshake) for all options.
+
+### Disable
+
+```ts
+export default defineConfig({
+  treeshake: false,
+})
+```
+
+## Side Effects
+
+### Package.json sideEffects
+
+Declare side effects in your package:
+
+```json
+{
+  "sideEffects": false
+}
+```
+
+Or specify files with side effects:
+
+```json
+{
+  "sideEffects": ["*.css", "src/polyfills.ts"]
+}
+```
+
+### Module Side Effects
+
+```ts
+export default defineConfig({
+  treeshake: {
+    moduleSideEffects: (id) => {
+      // Preserve side effects for polyfills
+      return id.includes('polyfill')
+    },
+  },
+})
+```
+
+## Common Patterns
+
+### Production Build
+
+```ts
+export default defineConfig({
+  entry: ['src/index.ts'],
+  format: ['esm', 'cjs'],
+  treeshake: true,
+  minify: true,
+})
+```
+
+### Development Build
+
+```ts
+export default defineConfig((options) => ({
+  entry: ['src/index.ts'],
+  treeshake: !options.watch,  // Disable in dev
+}))
+```
+
+### Library with Side Effects
+
+```ts
+export default defineConfig({
+  entry: ['src/index.ts'],
+  treeshake: {
+    moduleSideEffects: (id) => {
+      return (
+        id.includes('.css') ||
+        id.includes('polyfill') ||
+        id.includes('side-effect')
+      )
+    },
+  },
+})
+```
+
+### Utilities Library
+
+```ts
+export default defineConfig({
+  entry: ['src/index.ts'],
+  format: ['esm'],
+  treeshake: true,
+  dts: true,
+})
+```
+
+Users can import only what they need:
+```ts
+import { onlyWhatINeed } from 'my-utils'
+```
+
+## Benefits
+
+### Smaller Bundles
+
+- Only includes imported code
+- Removes unused functions, classes, variables
+- Reduces download size
+
+### Better Performance
+
+- Less code to parse
+- Faster execution
+- Improved loading times
+
+### Cleaner Output
+
+- No dead code in production
+- Easier to debug
+- Better maintainability
+
+## When to Disable
+
+### Debugging
+
+During development to see all code:
+
+```ts
+export default defineConfig((options) => ({
+  treeshake: !options.watch,
+}))
+```
+
+### Side Effect Code
+
+Code with global side effects:
+
+```ts
+// This has side effects
+window.myGlobal = {}
+
+export function setup() {
+  // ...
+}
+```
+
+Disable tree shaking or mark side effects:
+
+```json
+{
+  "sideEffects": true
+}
+```
+
+### Testing
+
+Include all code for coverage:
+
+```ts
+export default defineConfig({
+  treeshake: false,
+})
+```
+
+## Tips
+
+1. **Leave enabled** for production builds
+2. **Mark side effects** in package.json
+3. **Use with minification** for best results
+4. **Test tree shaking** - verify unused code is removed
+5. **Disable for debugging** if needed
+6. **Pure functions** are easier to tree shake
+
+## Troubleshooting
+
+### Code Still Included
+
+- Check for side effects
+- Verify imports are ES modules
+- Ensure code is actually unused
+- Check `sideEffects` in package.json
+
+### Missing Code at Runtime
+
+- Code has side effects but marked as none
+- Set `sideEffects: true` or list specific files
+
+### Unexpected Behavior
+
+- Module has side effects not declared
+- Try disabling tree shaking to isolate issue
+
+## Examples
+
+### Pure Utility Functions
+
+```ts
+// utils.ts - perfect for tree shaking
+export function add(a, b) {
+  return a + b
+}
+
+export function multiply(a, b) {
+  return a * b
+}
+
+// Only 'add' imported = only 'add' bundled
+import { add } from './utils'
+```
+
+### With Side Effects
+
+```ts
+// polyfill.ts - has side effects
+if (!Array.prototype.at) {
+  Array.prototype.at = function(index) {
+    // polyfill implementation
+  }
+}
+
+export {} // Need to export something
+```
+
+```json
+{
+  "sideEffects": ["src/polyfill.ts"]
+}
+```
+
+## Related Options
+
+- [Minification](option-minification.md) - Code compression
+- [Target](option-target.md) - Syntax transformations
+- [Dependencies](option-dependencies.md) - External packages
+- [Output Format](option-output-format.md) - Module formats