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/study/ResourcePane.jsx

@@ -16,7 +16,7 @@ export const RESOURCE_TABS = [
 export default function ResourcePane({ tab, setTab, chunk, chapter, chapterIndex, project, updateChunk, notify, resources, wordStudy, crossRefs, openWordId, setOpenWordId }) {
   const counts = { words: chunk.greekWords.length, refs: (chunk.crossReferences ?? []).length };
   return (
-    <div className="flex h-full min-h-0 flex-col">
+    <div className="flex min-h-0 flex-1 flex-col">
       <div role="tablist" aria-label="Study resources" className="flex shrink-0 flex-wrap gap-1.5 border-b border-[var(--r-line)] px-3 py-2.5">
         {RESOURCE_TABS.map((t) => (
           <button key={t.id} type="button" role="tab" aria-selected={tab === t.id} onClick={() => setTab(t.id)}