fix dark mode reset

[Utkarsh-rwt]

Fix popup dark mode reset by persisting theme state in chrome.storage.local and restoring it on initialization.

[Shantanugupta43]

Hey great work need a few changes and PR is good to merge.

[Shantanugupta43]

the function is nested inside initialize(). Cut it out and paste it above initialize() as its own function because No other part of your popup script can reuse it and It becomes harder to debug or extend later

[Shantanugupta43]

there may be an XSS risk the browser may interpret the text as HTML code. Would be better to make it

const strong = document.createElement('strong');
strong.textContent = 'Why: ';
derivationEl.appendChild(strong);
derivationEl.appendChild(document.createTextNode(derivation));

[Shantanugupta43]

the function is nested inside initialize(). Cut it out and paste it above initialize() as its own function so that because no other part of your popup script can reuse it and It becomes harder to debug or extend later.

[Utkarsh-rwt]

Fix 1 — loadDarkMode hoisted out of initialize(): It's now a standalone top-level async function loadDarkMode() declared before initialize(). The dark mode DOM variable declarations (sign, outer, inner, text) were also moved up alongside it so they're in scope when the function runs.
Fix 2 — XSS-safe derivation rendering: The derivationEl.innerHTML = <strong>Why: ${derivation}line is replaced with explicit DOM construction —createElement('strong')withtextContent, then createTextNode(derivation) appended separately — so user-supplied derivation text is never parsed as HTML.