feat(sdk): AI SDK custom useChat transport & chat.task harness #5173

Job	Run time
typecheck / typecheck	6m 43s
sdk-compat / Deno Runtime	2m 4s
e2e / 🧪 CLI v3 tests (ubuntu-latest - npm)	1m 50s
e2e / 🧪 CLI v3 tests (windows-latest - npm)	4m 13s
sdk-compat / Node.js 20.20 (ubuntu-latest)	2m 2s
e2e / 🧪 CLI v3 tests (windows-latest - pnpm)	4m 17s
sdk-compat / Node.js 22.12 (ubuntu-latest)	2m 1s
sdk-compat / Cloudflare Workers	2m 19s
e2e / 🧪 CLI v3 tests (ubuntu-latest - pnpm)	1m 54s
units / packages / 🧪 Unit Tests: Packages (1, 1)	9m 10s
sdk-compat / Bun Runtime	2m 4s
units / internal / 🧪 Unit Tests: Internal (6, 8)	6m 2s
units / internal / 🧪 Unit Tests: Internal (3, 8)	8m 52s
units / internal / 🧪 Unit Tests: Internal (7, 8)	5m 36s
units / webapp / 🧪 Unit Tests: Webapp (2, 8)	4m 15s
units / internal / 🧪 Unit Tests: Internal (8, 8)	2m 36s
units / internal / 🧪 Unit Tests: Internal (1, 8)	6m 51s
units / webapp / 🧪 Unit Tests: Webapp (8, 8)	2m 53s
units / internal / 🧪 Unit Tests: Internal (2, 8)	12m 43s
units / webapp / 🧪 Unit Tests: Webapp (3, 8)	6m 39s
units / webapp / 🧪 Unit Tests: Webapp (1, 8)	6m 0s
units / internal / 🧪 Unit Tests: Internal (4, 8)	6m 20s
units / webapp / 🧪 Unit Tests: Webapp (5, 8)	8m 5s
units / internal / 🧪 Unit Tests: Internal (5, 8)	6m 28s
units / webapp / 🧪 Unit Tests: Webapp (6, 8)	4m 14s
units / webapp / 🧪 Unit Tests: Webapp (4, 8)	3m 59s
units / webapp / 🧪 Unit Tests: Webapp (7, 8)	6m 18s
units / webapp / 📊 Merge Reports	41s
units / packages / 📊 Merge Reports	23s
units / internal / 📊 Merge Reports	28s
	2h 18m 0s

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