Ensure APP_HOSTNAME is set

[frankdekker]

On fresh dev installation APP_HOSTNAME is required

[Copilot]

Pull Request Overview

This PR adds the required APP_HOSTNAME configuration to the development environment file to ensure proper functionality on fresh development installations.

• Adds APP_HOSTNAME=localhost to the .env.dev file

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.98%. Comparing base (ca1e782) to head (0b7628c).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #1206   +/-   ##
=========================================
  Coverage     99.98%   99.98%           
  Complexity     3337     3337           
=========================================
  Files           580      580           
  Lines          9910     9910           
=========================================
  Hits           9909     9909           
  Misses            1        1           

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