test: stabilize stale cluster snapshot clock

[ammarheidari]

Summary

Stabilizes the pre-existing ClusterExplorerServiceTests.Retryable_refresh_failure_serves_stale_metadata_as_degraded test that is blocking the required quality gate for docs-only planning PR #147.

The test previously seeded the cached observation from real wall-clock UtcNow - 1500ms with a 1s TTL, leaving only ~500ms of stale-window budget while the coordinator deliberately performs up to three retryable reads with backoff/jitter. Slow runner scheduling can therefore cross StaleAfterUtc and correctly return Unavailable, making the assertion timing-dependent.

This change injects a deterministic TimeProvider into the coordinator and uses the same clock for the test observations. Production code, snapshot TTL semantics, retry behavior and v0.6 planning contracts are unchanged.

Scope

• test-only change in ClusterExplorerServiceTests.cs
• no production/runtime change
• no v0.6 implementation
• no release/version/workflow change

Evidence requested

Fresh exact-head repository CI and independent review. Do not merge until protected-main requirements are satisfied.

Relates to #146 and unblocks planning PR #147 quality-gate reconciliation.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-24T03:44:12.399315Z	fcb63c5	Manual request

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[ammarheidari]

@codex review

Please review exact head 562173ee08644d8bd076c3d7100001891b5184de. This is a test-only deterministic-clock stabilization for a pre-existing flaky stale-snapshot assertion; production behavior and v0.6 planning/runtime are unchanged.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Hooray!

Reviewed commit: 562173ee08

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[ammarheidari]

@codex review

Please perform a fresh exact-head review of 562173ee08644d8bd076c3d7100001891b5184de. Scope is test-only stabilization of the pre-existing stale-snapshot timing test; production/runtime semantics must remain unchanged.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Chef's kiss.

Reviewed commit: 562173ee08

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[ammarheidari]

PM exact-head reconciliation on 562173ee08644d8bd076c3d7100001891b5184de: reviewed the one-file test-only patch and current exact-head evidence. The change replaces wall-clock sampling in the flaky stale-snapshot test with the same injected TimeProvider used by KafkaSnapshotCoordinator; no production/runtime file, TTL/retry contract, workflow, version, release identity, or v0.6 implementation surface is changed. Exact-head quality-gate, dependency-review, v03-benchmark, and v04-benchmark are successful; Codex exact-head review completed with no findings and review threads are clear. This COMMENT is PM evidence only, not an approval and does not substitute for the required independent CODEOWNER approval from akhiabanchian.

[ammarheidari]

@codex review

Fresh review requested after reconciling PR #149 with protected main 9a6d3557fd9a954b1fa72a2a8c971a7d7b8481fa. New exact head: 71ceef5bab6f9d368eef976c0fb56479771f5106.

[ammarheidari]

@codex review

Fresh review requested after replacing the non-conventional reconciliation merge subject. Content/tree is unchanged from the prior synchronized head; exact head is now fcb63c542bc67a81e93207fc0157777694255c27 on protected main 9a6d3557fd9a954b1fa72a2a8c971a7d7b8481fa.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Can't wait for the next one!

Reviewed commit: fcb63c542b

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