Add typing for AppSec::Response#to_rack, HashCoercion, and Forking

[marcotc]

What does this PR do?

• AppSec::Response#to_rack: ::Array[untyped] → precise [::Integer, ::Hash[::String, ::String], ::Array[::String]] tuple matching the status/headers/body attribute types
• AppSec::Utils::HashCoercion#coerce: parameter and hash types use any (accepts any Ruby object, returns any hash)
• Core::Utils::Forking: included/extended accept ::Module and return void (standard included/extended hook pattern)

How to test the change?

bundle exec steep check \
  lib/datadog/appsec/response.rb \
  lib/datadog/appsec/utils/hash_coercion.rb \
  lib/datadog/core/utils/forking.rb

Changelog

None.

[github-actions]

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^{Visited at: 2026-03-13 20:32:20 UTC}

[github-actions]

Typing analysis

Note: Ignored files are excluded from the next sections.

Untyped methods

This PR clears 2 partially typed methods. It increases the percentage of typed methods from 61.19% to 61.29% (+0.1%).

Partially typed methods (+0-2)

✅ Cleared:

sig/datadog/appsec/response.rbs:12
└── def to_rack: () -> ::Array[untyped]
sig/datadog/appsec/utils/hash_coercion.rbs:5
└── def self.coerce: (untyped) -> ::Hash[untyped, untyped]?

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 95.16% (+0.01%)

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[Strech]

@marcotc advice learned by failure - you have to run steep with all project files, otherwise changes might break contracts that will be not verified on few files run.