feat: Adds api integration tests

[m3rchant-man]

Description

• Adds a run_tests.sh script to automate environment setup and test execution.
• Includes initial tests for the /health and /register endpoints.

Running

1. Ensure python3 is installed.
2. Run the following command to build the test environment and execute the tests:

   bash _scripts/run_tests.sh --build

3. Verify that all tests pass, as shown in the example output below.

Example run

$ bash run_tests.sh --build
Setting up Python virtual environment...
Creating virtual environment at /home/merchant/Documents/Project/openchampPS/tests/.venv...
Installing dependencies from /home/merchant/Documents/Project/openchampPS/tests/requirements.txt...
...

...
Installing collected packages: urllib3, pluggy, packaging, iniconfig, idna, charset-normalizer, certifi, requests, pytest
Successfully installed certifi-2025.10.5 charset-normalizer-3.4.4 idna-3.11 iniconfig-2.3.0 packaging-25.0 pluggy-1.6.0 pytest-8.2.0 requests-2.31.0 urllib3-2.5.0
Setup complete.
Running integration tests...
============================================================================================================ test session starts =============================================================================================================
platform linux -- Python 3.12.3, pytest-8.2.0, pluggy-1.6.0
rootdir: /home/merchant/Documents/Project/openchampPS
collected 3 items                                                                                                                                                                                                                            

../tests/test_api.py ...                                                                                                                                                                                                               [100%]

============================================================================================================= 3 passed in 0.11s ==============================================================================================================