test: add Pest v1 security test infrastructure

[somethingwithproof]

Separates the Pest security test infrastructure into its own PR as requested.

[Copilot]

Pull request overview

This PR introduces a Pest-based security test scaffold for the MikroTik plugin, aiming to add lightweight static checks over key plugin files without requiring a full Cacti runtime.

Changes:

• Adds a Pest bootstrap/config entrypoint (tests/Pest.php, tests/bootstrap.php) with basic Cacti function stubs.
• Adds security-oriented Pest tests to validate setup.php structure, enforce prepared-statement usage, and guard against PHP 8+ syntax usage.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/Security/SetupStructureTest.php	Adds assertions about required setup.php functions and version metadata presence.
tests/Security/PreparedStatementConsistencyTest.php	Adds a static scan intended to forbid raw db_execute/db_fetch_* calls.
tests/Security/Php74CompatibilityTest.php	Adds static scans for a small set of PHP 8.0+ syntax/API usage.
tests/Pest.php	Adds Pest entrypoint requiring the test bootstrap.
tests/bootstrap.php	Adds a test bootstrap with stubs for selected Cacti/DB helper functions/constants.

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