👺 Havoc: Prevent panic on jittered_ttl overflow

[madmax983]

🧊 The Trigger:
Passing a very large Duration (e.g. Duration::MAX) to jittered_ttl with a fraction that results in a randomized jitter factor > 1.0.

📉 The Stack Trace:

thread 'integration::chaos_cache_jitter_proptest::test_jittered_ttl_no_panic' panicked at /rustc/4a4ef493e3a1488c6e321570238084b38948f6db/library/core/src/time.rs:964:23:
cannot convert float seconds to Duration: value is either too big or NaN

🧪 Reproduction:
Run the new proptest harness located at autumn/tests/integration/chaos_cache_jitter_proptest.rs. The fuzzer hits this edge case by feeding extreme ranges into jittered_ttl.

😈 Comment:
"You assumed Duration::mul_f64 was infallible and would never overflow when multiplying large durations by random jitter. You were wrong."

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PR created automatically by Jules for task 257098097593059716 started by @madmax983

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[gemini-code-assist]

Code Review

This pull request prevents potential panics in jittered_ttl due to overflow when multiplying a large Duration by a random jitter factor, and adds a property-based test to verify this safety. The feedback suggests using Duration::try_from_secs_f64 to perform a cleaner, safer, and more idiomatic checked conversion instead of manually checking against u64::MAX as f64 and suppressing the clippy::cast_precision_loss lint.

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[gemini-code-assist]

Instead of manually checking for overflow against u64::MAX as f64 (which requires suppressing the clippy::cast_precision_loss lint), you can use Duration::try_from_secs_f64 directly. This is cleaner, safer, and idiomatic in Rust for performing checked float-to-Duration conversions.

    Duration::try_from_secs_f64(base.as_secs_f64() * factor).unwrap_or(Duration::MAX)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.82%. Comparing base (14e6518) to head (f4e25c5).

Additional details and impacted files

@@              Coverage Diff              @@
##           trunk-dev    #1807      +/-   ##
=============================================
- Coverage      86.82%   86.82%   -0.01%     
=============================================
  Files            273      273              
  Lines         202424   202427       +3     
=============================================
  Hits          175761   175761              
- Misses         26663    26666       +3     

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