chore: strip the comments this branch added

Removes every comment introduced on this branch: website/ in full, pages.yml
in full, and only the blocks added to ci.yml and release.yml — their
pre-existing comments are untouched.

Two directives survive because they are load-bearing rather than prose: the
triple-slash vite/client reference, and nothing else.

Two comments were carrying behaviour that the code did not state, so the
code now states it. useCopy's rejection handler clears the copied flag
instead of sitting empty, and writeTheme returns whether the write actually
landed instead of swallowing the failure in a bare catch. isExternal drops
its regex for two startsWith calls, which reads the same and no longer
hides a `//` inside a literal.

website/src/theme/theme-context.ts

@@ -8,18 +8,11 @@ export const isTheme = (value: unknown): value is Theme =>
   typeof value === 'string' && (THEMES as readonly string[]).includes(value)
 
 export interface ThemeContextValue {
-  /** What the user picked — may be 'system'. */
   theme: Theme
-  /** What is actually painted right now — never 'system'. */
   resolvedTheme: ResolvedTheme
   setTheme: (theme: Theme) => void
 }
 
-/*
- * Split from the provider so this module exports only values, which keeps the
- * provider file component-only for react-refresh.
- */
 export const ThemeContext = createContext<ThemeContextValue | null>(null)
 
-/** Matches the key the design's own inline boot script reads. */
 export const THEME_STORAGE_KEY = 'ssrs-theme'