⚡ Optimize iframe selection using getElementsByTagName

[NDevTK]

💡 What: Replaced document.querySelectorAll('iframe') with document.getElementsByTagName('iframe') and updated the iteration to use a for...of loop.

🎯 Why: getElementsByTagName is generally faster than querySelectorAll for simple tag name lookups because it returns a live HTMLCollection directly from the DOM implementation without needing to parse a CSS selector string or traverse the full tree to build a static snapshot. This optimization is particularly relevant for initialization scripts that run on page load.

📊 Measured Improvement:
While benchmark results in a JSDOM environment were mixed due to JSDOM's specific implementation of live collections versus static lists, this change is a standard optimization practice for browser environments (Chrome/Firefox) where getElementsByTagName is highly optimized. Correctness was verified using a custom integration test in JSDOM, ensuring all iframes are still correctly hooked without errors.

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PR created automatically by Jules for task 7774213346520338112 started by @NDevTK

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