fix: resolve flash of unstyled content in dark mode

[TusharThakur04]

Description

This PR resolves the FOUC by resolving system to dark or light using matchMedia.
Earlier system was directly being applied as set-theme = system

Validation

before :

Screencast.from.2026-04-13.19-26-34.webm

after :

Screencast.from.2026-04-13.19-24-03.webm

Related Issues

n/a

Check List

• I have read the Contributing Guidelines and made commit messages that follow the guideline.
• I have run node --run test and all tests passed.
• I have check code formatting with node --run format & node --run lint.
• I've covered new added functionality with unit tests if necessary.

[cursor]

PR Summary

Low Risk
Low risk: a small inline script change in the HTML template that only affects initial theme selection and color-scheme styling before hydration.

Overview
Fixes initial theme bootstrapping in template.html to resolve a stored theme=system preference into the actual OS dark/light value via matchMedia before setting data-theme and colorScheme.

This prevents the page from briefly rendering with an invalid system theme value and reduces dark-mode FOUC on load.

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Project	Deployment	Actions	Updated (UTC)
api-docs-tooling	Ready	Preview	Apr 13, 2026 2:30pm

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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