fix(codex): raise GPT-6.1 Sol generated context default to 500k

[Larry-Labs]

When Codex uses Sub2API's generated GPT-6.1 Sol catalog (including an API-key model endpoint that omits context metadata), it still receives the bundled 272,000-token default and may compact earlier than the newly announced Codex/Work default.

Set the generated default to 500,000 tokens. Keep the pinned official JSON snapshot intact, preserve explicit upstream context values, and leave the existing maximum-window and billing policies unchanged. Regression coverage checks the offline catalog, missing/null API-key context metadata, lower/higher explicit upstream windows, and byte-for-byte OAuth manifest passthrough.

Related: #8032. The change follows the October 12 announcement reported there; the checked-in openai/codex static catalog still advertises the older default. This is a generated-catalog default update, not evidence that every upstream account has received the rollout.

Validation (October 12, 2026, macOS arm64 / Go 1.27.2):

• Passed: targeted GPT-6.1 Sol/catalog regression tests from the original submission.
• Passed: full integration suite, CI=true CGO_ENABLED=0 GOPROXY=https://goproxy.cn DOCKER_HOST=unix:///Users/xugao/.colima/default/docker.sock TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE=/var/run/docker.sock go test -p 1 -tags=integration ./.... PostgreSQL 18.1 and Redis 8.4 test containers ran; Docker-unavailable skipping was prevented with CI=true.
• Passed: CGO_ENABLED=0 GOPROXY=https://goproxy.cn golangci-lint run --concurrency 2 --timeout 30m ./..., using CI's golangci-lint v2.14.0; 0 issues.
• Passed: gofmt and git diff --check.
• Full unit suite FAILED: CGO_ENABLED=0 GOPROXY=https://goproxy.cn go test -p 2 -tags=unit ./..., then the complete suite retried with -parallel 1. Both runs failed only TestInflightEstimate_AccountMappingNoDBAndBoundedMemory at billing_inflight_reservation_test.go:464: heap growth 8,575,720 / 8,589,064 bytes exceeded the unchanged 8,388,608-byte assertion. All other test packages passed. The isolated test passed three consecutive runs on both the PR and parent revision. The complete parent-revision service package passed with -parallel 1 (220.999s), so the failure is not established as pre-existing. A subsequent isolated full PR unit run (-p 1 -parallel 1) passed the memory assertion but failed TestShouldAutoPauseGrokAccountByQuota/retry_after_active; that test uses parallel subtests and a 30-second real-time expiry, which can be sensitive to forced test serialization. The final full retry restored default test parallelism (go test -p 1 -tags=unit ./...) and again failed only the unchanged memory assertion. Root cause remains unresolved; no assertion was weakened, no test excluded, and the complete unit suite is NOT marked passing.
• Initial integration attempt failed on Docker Hub EOF and Colima reaper startup. The full retry used cached images and the correct in-VM Docker socket path and passed; project source/configuration was unchanged.
• CGO was disabled because the local Xcode license is not accepted, consistent with the backend build target. No live 500k-token upstream request was run.

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[Larry-Labs]

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