feat(sdk): AI SDK chat transport — run useChat as tasks #4710

Job	Run time
sdk-compat / Bun Runtime	1m 36s
typecheck / typecheck	1m 46s
sdk-compat / Node.js 20.20 (ubuntu-latest)	1m 37s
sdk-compat / Node.js 22.12 (ubuntu-latest)	1m 43s
e2e / 🧪 CLI v3 tests (ubuntu-latest - pnpm)	1m 46s
e2e / 🧪 CLI v3 tests (ubuntu-latest - npm)	1m 42s
e2e / 🧪 CLI v3 tests (windows-latest - pnpm)	1m 39s
e2e / 🧪 CLI v3 tests (windows-latest - npm)	1m 34s
sdk-compat / Cloudflare Workers	1m 42s
sdk-compat / Deno Runtime	1m 49s
units / packages / 🧪 Unit Tests: Packages (1, 1)	1m 35s
units / internal / 🧪 Unit Tests: Internal (8, 8)	1m 48s
units / webapp / 🧪 Unit Tests: Webapp (2, 8)	1m 48s
units / webapp / 🧪 Unit Tests: Webapp (5, 8)	1m 48s
units / webapp / 🧪 Unit Tests: Webapp (3, 8)	1m 49s
units / webapp / 🧪 Unit Tests: Webapp (8, 8)	1m 37s
units / internal / 🧪 Unit Tests: Internal (2, 8)	1m 48s
units / internal / 🧪 Unit Tests: Internal (4, 8)	1m 48s
units / webapp / 🧪 Unit Tests: Webapp (7, 8)	1m 47s
units / internal / 🧪 Unit Tests: Internal (1, 8)	1m 37s
units / webapp / 🧪 Unit Tests: Webapp (1, 8)	1m 48s
units / internal / 🧪 Unit Tests: Internal (5, 8)	1m 34s
units / webapp / 🧪 Unit Tests: Webapp (4, 8)	1m 42s
units / internal / 🧪 Unit Tests: Internal (3, 8)	1m 36s
units / webapp / 🧪 Unit Tests: Webapp (6, 8)	1m 48s
units / internal / 🧪 Unit Tests: Internal (7, 8)	1m 48s
units / internal / 🧪 Unit Tests: Internal (6, 8)	1m 48s
units / packages / 📊 Merge Reports	1s
units / internal / 📊 Merge Reports	1s
units / webapp / 📊 Merge Reports	1s
	46m 26s

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