Refactored the public site into feature-owned sections and stylesheets while keeping the published content unchanged.

Refreshed Firefox, Chrome, and Tampermonkey packaged builds for version 1.1.15.

Speed & Loop now saves positive playback speed per domain and reapplies it across tabs on the same site. If you set YouTube to 2x
in one tab, another YouTube tab can pick up 2x automatically when it becomes active or visible. Saved domain speed is also
reapplied when media elements are attached or their source changes, improving speed persistence during YouTube video navigation.

This release also fixes shortcut behavior after video navigation so the next speed adjustment starts from the restored domain speed
instead of a stale internal value.

Improved Firefox loading reliability by moving extension injection to the active tab and active frame lifecycle.
The Firefox popup UI has been removed; playback controls continue to appear directly on supported media. This
release also adds frame-aware loading and rescanning so media created after page load, YouTube SPA navigation, and
embedded video frames can be initialized more consistently.

It also fixes the default enabled state so a fresh install is treated as enabled when no saved setting exists yet.

Fixed the Firefox version so Speed & Loop loads automatically when a supported page, such as YouTube, is opened. The video controller and keyboard shortcuts now initialize without requiring the extension toolbar button to be clicked. Also prevented duplicate content script injection when the toolbar button is clicked after the page has already been initialized.

Updated the extension icons to use transparent-background assets.
Improved the release build process so package versions are updated automatically during compilation.
Updated Firefox and Chrome manifest versions consistently during release builds.
Removed macOS metadata files from packaged ZIP artifacts.

Version 1.0.12 adds an optional “Keep speed sites” setting for players that repeatedly override playback speed.

Changes:
- Added a Keep speed sites field in the options page.
- Keep-speed enforcement is disabled by default.
- When a matching host is registered, the extension periodically reapplies the selected playback speed.
- This is intended for sites such as nicovideo.jp where the page may reset video.playbackRate during playback.
- Added support packaging cleanup for the Firefox build.