Add comprehensive webapp testing skills #5351

Job	Run time
typecheck / typecheck	2m 29s
sdk-compat / Cloudflare Workers	2m 5s
sdk-compat / Deno Runtime	1m 56s
e2e / 🧪 CLI v3 tests (ubuntu-latest - pnpm)	1m 57s
sdk-compat / Node.js 20.20 (ubuntu-latest)	1m 58s
e2e / 🧪 CLI v3 tests (ubuntu-latest - npm)	1m 42s
e2e / 🧪 CLI v3 tests (windows-latest - pnpm)	2m 14s
sdk-compat / Bun Runtime	1m 59s
units / packages / 🧪 Unit Tests: Packages (1, 1)	2m 26s
sdk-compat / Node.js 22.12 (ubuntu-latest)	2m 2s
e2e / 🧪 CLI v3 tests (windows-latest - npm)	2m 13s
units / internal / 🧪 Unit Tests: Internal (2, 8)	2m 24s
units / internal / 🧪 Unit Tests: Internal (6, 8)	2m 25s
units / internal / 🧪 Unit Tests: Internal (3, 8)	2m 23s
units / internal / 🧪 Unit Tests: Internal (5, 8)	2m 24s
units / internal / 🧪 Unit Tests: Internal (1, 8)	2m 24s
units / internal / 🧪 Unit Tests: Internal (7, 8)	2m 25s
units / internal / 🧪 Unit Tests: Internal (8, 8)	2m 25s
units / webapp / 🧪 Unit Tests: Webapp (4, 8)	2m 24s
units / webapp / 🧪 Unit Tests: Webapp (2, 8)	2m 25s
units / webapp / 🧪 Unit Tests: Webapp (6, 8)	2m 24s
units / webapp / 🧪 Unit Tests: Webapp (7, 8)	2m 27s
units / webapp / 🧪 Unit Tests: Webapp (8, 8)	2m 48s
units / webapp / 🧪 Unit Tests: Webapp (5, 8)	2m 26s
units / webapp / 🧪 Unit Tests: Webapp (1, 8)	2m 24s
units / webapp / 🧪 Unit Tests: Webapp (3, 8)	2m 24s
units / internal / 🧪 Unit Tests: Internal (4, 8)	2m 28s
units / packages / 📊 Merge Reports	1s
units / internal / 📊 Merge Reports	1s
units / webapp / 📊 Merge Reports	1s
	1h 2m 4s

Provide feedback