#583 Make Trace array thread-safe with Mutex

[VasilevNStas]

Problem

The @trace array in Fbe::Middleware::Trace is accessed from multiple threads without synchronization. When Octokit fires concurrent requests, a race condition occurs: simultaneous read/write on @trace can corrupt the data.

Solution

1. Trace middleware (lib/fbe/middleware/trace.rb):

   • Added @mutex = Mutex.new in constructor
   • All @trace reads/writes wrapped with @mutex.synchronize

2. Decoor (lib/fbe/middleware/trace.rb):

   • Added trace_mutex parameter to print_trace!
   • @trace.clear wrapped with @mutex.synchronize

3. Octo (lib/fbe/octo.rb):

   • Created trace_mutex = Mutex.new
   • Passed to Trace middleware constructor and print_trace! call

4. Rubocop (.rubocop.yml):

   • Added trace_mutex to Elegant/GoodVariableName AllowedNames

Tests

90 tests, 0 failures, 0 errors, 2 skips

Closes #583

[VasilevNStas]

@yegor256 please review

[yegor256]

@VasilevNStas can't you call it just mutex? read: https://www.yegor256.com/2015/01/12/compound-name-is-code-smell.html

[VasilevNStas]

@yegor256

Renamed trace_mutex to mutex as suggested. Thanks for the reference
plz review