Fix skillmap losing high contrast theme on page refresh

[Copilot]

Enabling High Contrast from a skillmap tutorial and then refreshing the page dropped the skillmap back to the default color scheme.

High contrast is applied through color themes: ThemeManager.switchColorTheme() adds the high-contrast/hc classes to document.body, and all skillmap overrides (App.css, skillgraph.css, infopanel.css, ...) are keyed off .high-contrast. The skillmap App still had legacy code that removed that class on every React update whenever the deprecated state.auth.preferences?.highContrast redux value was falsy — which it almost always is, since preferences are only dispatched during cloud sync. So the restored high contrast theme was stripped of its class-based styling right after load.

// before: ran on every update, fighting ThemeManager
componentDidUpdate() {
    const { highContrast } = this.props; // undefined at load
    ...
    else if (bodyIsHighContrast) document.body.classList.remove("high-contrast");
}

skillmap/src/App.tsx

• Removed the manual body class manipulation; the class is owned by ThemeManager. Dropped the now-unused highContrast prop.
• initColorThemeAsync() reads the persisted theme id and the legacy high contrast flag straight from user preferences (props aren't populated at mount), mirroring the webapp's startup logic, and falls back to the stored/default theme when a target defines no high contrast theme.
• Re-applies the persisted theme when an activity closes, since the theme can be changed inside the editor iframe — the map now matches without requiring a refresh.
• changeTheme() clears the legacy highContrast preference when switching to a non-high-contrast theme (as the webapp does), so it can't override the theme preference on the next load.

skillmap/src/lib/authClient.ts

• Added getHighContrastPrefAsync().
• setColorThemeIdAsync() patches with { immediate: true }, matching the language/high-contrast setters, so a theme picked in the skillmap isn't lost to the 1s sync debounce on a quick refresh.

• Fixes #7624

[Joey Wunderlich (jwunderl)]

copilot was almost there but still not quite working, because that old special case for highContrast mode pre- theme implementation was still overriding via that sethighcontrast message. All appears to be working properly after my last commit / change, build based off as of now latest commit https://arcade.makecode.com/app/73c03d3dfba36ab1b2fa902d7f6183fdaccda319-f65e9a4e2a--skillmap