Rework app bar, notes layout, Settings/Admin/login restyle

App bar: brand, Studies / Read Bible / Reading Plans, and one account menu
(theme, Settings, Admin, Log out). Study stage: notes get their own box above
the resources in the right column. Settings, Admin and the login page use the
reader themes; add a theme-aware danger colour.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/reader/SearchSheet.jsx

@@ -68,7 +68,7 @@ export default function SearchSheet({
       {scope === 'bible' && isLocal && (
         <>
           {indexStatus === 'loading' && note('Loading the full Bible for search. This happens once per visit (about 7 MB).')}
-          {indexStatus === 'error' && <p className="text-sm text-red-600">Couldn’t load the full Bible. <button type="button" onClick={onLoadIndex} className="underline">Try again</button></p>}
+          {indexStatus === 'error' && <p className="text-sm text-[var(--r-danger,#b42318)]">Couldn’t load the full Bible. <button type="button" onClick={onLoadIndex} className="underline">Try again</button></p>}
           {indexStatus === 'ready' && (!deferredBibleQuery
             ? note('Type a word to search all 66 books.')
             : bibleMatches.length === 0
@@ -87,7 +87,7 @@ export default function SearchSheet({
       {scope === 'bible' && !isLocal && (
         <>
           {remote.tooShort && note('Type at least two letters. Use quotes for an exact phrase, like “good shepherd”.')}
-          {!remote.tooShort && remote.error && <p className="text-sm text-red-600">{remote.error}</p>}
+          {!remote.tooShort && remote.error && <p className="text-sm text-[var(--r-danger,#b42318)]">{remote.error}</p>}
           {!remote.tooShort && !remote.error && remote.loading && remote.results.length === 0 && note('Searching…')}
           {!remote.tooShort && !remote.error && !remote.loading && remote.total === 0 && remote.page > 0 && note(`No verses match “${query}”.`)}
           {remote.results.length > 0 && (