Expose browser pool warmup configuration

[IlyaasK]

Summary

• expose computed start_url, timeout_seconds, and fill_rate_per_minute
• distinguish omission from explicit null/malformed SDK values
• enforce timeout 10 through 259200 and non-negative fill rate
• preserve known zero through Terraform Framework state
• update generated Registry docs

Scope

Additive v1 durable read-only state only. Viewport, Chrome policy, runtime state, and live acceptance remain separate.

Tests

Ran focused tests repeatedly, race tests, full short suite, vet, gofmt, module verification/tidy diff, Terraform example fmt, docs drift, and diff checks.

Coverage includes Framework known zero, all omitted fields as typed null, inclusive timeout bounds, explicit null, wrong types, empty URL, and out-of-range values.

Acceptance not run; live response/project-scope proof remains deferred to opt-in acceptance tests.

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Note

Low Risk
Additive read-only data source attributes and validation on API response flattening; no resource writes or auth changes.

Overview
The kernel_browser_pool data source now surfaces three additional computed warmup fields from durable pool config: start_url, timeout_seconds, and fill_rate_per_minute, with matching Registry docs.

Flattening follows the same optional-field pattern as existing launch settings: omitted SDK JSON becomes Terraform null; explicit null, wrong types, or invalid values raise diagnostics instead of silently coercing state. timeout_seconds must be between 10 and 259200; fill_rate_per_minute must be ≥ 0, including preserving a known 0 in Framework state. Unit tests cover schema attributes, read wiring, boundary values, and rejection cases.

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