feat: add Pool column to browsers list

[masnwilliams]

Summary

• Add a "Pool" column to kernel browsers list table output showing the pool ID for browsers acquired from a pool (or "-" for regular browsers)
• Uses SDK ExtraFields to extract pool_id until the Go SDK is regenerated with the new field

Depends on kernel/kernel#1286 for the API to return pool_id.

Test plan

• kernel browsers list with pooled browsers shows pool ID in Pool column
• kernel browsers list with regular browsers shows "-" in Pool column
• kernel browsers list --output json includes pool_id for pooled browsers

Made with Cursor

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Note

Low Risk
Low risk: CLI-only output change plus a minor SDK version bump; the main impact is altered table columns/order and reliance on the updated SDK response shape for Pool.

Overview
Adds a new "Pool" column to kernel browsers list table output, populating it from browser.Pool (name preferred, then ID, else -).

Bumps github.com/kernel/kernel-go-sdk from v0.39.0 to v0.40.0 (with corresponding go.sum updates) to support the new field in list responses.

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[kernel-internal]

🔧 CI Fix Available

I've pushed a fix for the CI failure. The issue was that the replace directive in go.mod pointed to a private repository (github.com/stainless-sdks/kernel-go) that CI cannot access.

The fix removes the replace directive and uses the SDK's ExtraFields mechanism to extract pool data from the API response, which works with the public SDK.

👉 Click here to create a PR with the fix

[Sayan-]

changes lgtm - one suggestion. once we publish the new sdk please re-request review and we'll 🚢

[Sayan-]

changes lgtm! once we release and update the sdk dep I'll approve