fix(deps): update module github.com/cep21/circuit/v4 to v4.1.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
github.com/cep21/circuit/v4	v4.0.0 → v4.1.0

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Release Notes

cep21/circuit (github.com/cep21/circuit/v4)

v4.1.0

Compare Source

Bug-fix release: 24 bugs fixed across the circuit state machine, rolling metrics, and configuration factories. No breaking API changes (verified with gorelease). Requires Go 1.21+.

Bug fixes

Panics (crash → safe return)

• SortedDurations.Percentile(NaN) panicked with index-out-of-range (#​152)
• RollingCounter.GetBuckets panicked on zero-value counter — divide by zero (#​151)
• RollingCounter.UnmarshalJSON panicked on incomplete JSON; now errors (#​151)
• RollingCounter.UnmarshalJSON accepted inconsistent JSON (NumBuckets ≠ len(Buckets)), later GetBuckets panicked; now errors at unmarshal (#​152)
• Opener.SetConfigNotThreadSafe panicked on nil Now func (#​151)
• RollingBuckets.Advance panicked on zero BucketWidth (#​150)
• RollingPercentile.AddDuration panicked on times before StartTime (#​150)

Data races (fixed under -race)

• ConsecutiveErrOpenerFactory: closure captured config by reference — concurrent factory calls mutated shared state (#​151)
• hystrix.OpenerFactory and CloserFactory: same closure-capture bug (#​150)
• RollingBuckets.Advance: concurrent callers could clear the same bucket multiple times or skip clears (#​150)

Incorrect behavior

• Circuit open/close TOCTOU: concurrent state transitions could emit Opened()/Closed() metric callbacks multiple times per transition. Now uses CAS to guarantee exactly-once (#​151)
• Fallback concurrency throttle read MaxConcurrentRequests twice; a config change between reads could produce inconsistent gating (#​151)
• Circuit.OpenCircuit used time.Now() instead of the configured TimeKeeper (#​150)
• Duplicate now() calls at the timeout boundary could mark an on-time completion as a spurious timeout (#​150)
• SortedDurations.Var reported percentiles with wrong scaling (#​150)
• MockClock.AfterFunc with negative duration never fired — real time.AfterFunc fires immediately (#​151)
• IsBadRequest did not unwrap wrapped errors — now uses errors.As (#​150)

Dead code / cleanup (#​150)

• Removed unreachable branches and unused fields flagged by static analysis.

Testing

• Property-based state-machine test (testing/quick + MockClock + reference model) verifies the exactly-once RunMetrics contract and Opened/Closed alternation under all interleavings (#​152)
• 5 Go-native fuzz targets with differential oracle for RollingCounter, RollingBuckets, SortedDurations.Percentile (#​152)
• Invariant-asserting concurrent stress tests that would have caught the TOCTOU bugs pre-merge (#​152)
• Daily scheduled fuzzing workflow (#​152)

Tooling

• Makefile restored: make (fast loop), make ci (pre-PR gate), make fuzz, make bench, make cover (#​152)

Full changelog: cep21/circuit@v4.0.0...v4.1.0

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