Chore: Test: Add test for querying items with special character IDs

[Bappoz]

This PR adds a unit test suite covering the static method isSystemPath(path) from the BaseItem class, based on the MC/DC (Modified Condition/Decision Coverage) criterion. The tests ensure that each individual condition independently affects the outcome of the decision logic.
Test cases included

• CT1: All conditions true → expected return: true
• CT2: path is empty → expected return: false
• CT3: path has no dot → expected return: false
• CT4: name.length < 32 → expected return: false
• CT5: ext !== 'md' → expected return: false

[github-actions]

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[personalizedrefrigerator]

Thank you for the pull request!

Feedback:

• Be sure that code passes the linter.
• Be sure that the code passes the typechecker prior to committing.
• Usually, the .test.ts files should have a single describe block per file.
• Test names should use English and usually should be in the form it('should ...'.
• Consider using the test.each pattern when there are many similar tests with different inputs/outputs.