feat(appsec): support transaction id header for request tracing

[LaurenceJJones]

fix #3997

Allow incoming HTTP requests to provide a custom transaction ID via X-Crowdsec-Appsec-Transaction-Id header. This ID will be used for both inband and outband processing, enabling consistent request tracing across web server logs and CrowdSec logs.

• Extract transaction ID from X-Crowdsec-Appsec-Transaction-Id header if present
• Fall back to generating UUID if header is not provided (backward compatible)
• Remove header before passing to Coraza (consistent with other special headers)
• Same transaction ID used for both inband and outband Coraza transactions

[github-actions]

@LaurenceJJones: There are no 'kind' label on this PR. You need a 'kind' label to generate the release automatically.

• /kind feature
• /kind enhancement
• /kind refactoring
• /kind fix
• /kind chore
• /kind dependencies

Details

I am a bot created to help the crowdsecurity developers manage community feedback and contributions. You can check out my manifest file to understand my behavior and what I can do. If you want to use this for your project, you can check out the BirthdayResearch/oss-governance-bot repository.

[github-actions]

@LaurenceJJones: There are no area labels on this PR. You can add as many areas as you see fit.

• /area agent
• /area local-api
• /area cscli
• /area appsec
• /area security
• /area configuration

Details

I am a bot created to help the crowdsecurity developers manage community feedback and contributions. You can check out my manifest file to understand my behavior and what I can do. If you want to use this for your project, you can check out the BirthdayResearch/oss-governance-bot repository.

[LaurenceJJones]

/kind enhancement
/area appsec

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.85%. Comparing base (db3efdb) to head (647466b).
⚠️ Report is 7 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4124      +/-   ##
==========================================
- Coverage   62.87%   62.85%   -0.03%     
==========================================
  Files         464      464              
  Lines       33286    33290       +4     
==========================================
- Hits        20929    20924       -5     
- Misses      10237    10243       +6     
- Partials     2120     2123       +3     

Flag	Coverage Δ
bats	46.21% <100.00%> (+0.01%)	⬆️
unit-linux	35.58% <0.00%> (-0.11%)	⬇️
unit-windows	25.04% <0.00%> (-0.01%)	⬇️

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