fix(express): honor configured trust proxy hop count (#3933)

[PierreBrisorgueil]

Problem

initMiddleware treated config.trust.proxy as a boolean gate then always set Express trust proxy to fully-permissive true, discarding the configured hop count. production.config.js sets trust.proxy: 1, but that 1 was thrown away → req.ip derived from the client-controlled leftmost X-Forwarded-For → the IP-keyed auth rate limiter (login/forgot/signup) is bypassable by rotating a spoofed header (ERR_ERL_PERMISSIVE_TRUST_PROXY).

Fix

Forward the configured value: app.set('trust proxy', config.trust.proxy). A boolean true still fully-trusts the chain; a numeric hop count like 1 is now honored so req.ip resolves to the real socket IP. Falsy values still leave Express at its safe default.

Test

Added express trust-proxy unit tests: hop count survives (not collapsed to true), the compiled fn trusts the immediate proxy but not a further client-controlled hop, booleans still work, falsy leaves the default.

Closes #3933

https://claude.ai/code/session_01V1mhCDsSUnn3WGtevd3YFX

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📥 Commits

Reviewing files that changed from the base of the PR and between 7916876 and 23f0488.

📒 Files selected for processing (2)

• lib/services/express.js
• lib/services/tests/express.trustProxy.unit.tests.js

✨ Finishing Touches

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• Create PR with unit tests
• Commit unit tests in branch fix/trust-proxy-honor-hopcount

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.67%. Comparing base (7916876) to head (23f0488).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3936   +/-   ##
=======================================
  Coverage   92.67%   92.67%           
=======================================
  Files         169      169           
  Lines        5546     5546           
  Branches     1782     1783    +1     
=======================================
  Hits         5140     5140           
  Misses        326      326           
  Partials       80       80           

Flag	Coverage Δ
integration	61.07% <100.00%> (ø)
unit	74.28% <100.00%> (ø)

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