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/NotesPane.jsx

@@ -50,7 +50,7 @@ export default function NotesPane({ chunk, updateChunk, allTags }) {
             </button>
             {isOpen && (
               <div className="px-4 pb-4">
-                <textarea aria-label={label} value={chunk[field] ?? ''} rows={8} placeholder={placeholder}
+                <textarea aria-label={label} value={chunk[field] ?? ''} rows={7} placeholder={placeholder}
                   onChange={(e) => updateChunk(chunk.id, { [field]: e.target.value })} className={areaCls} />
               </div>
             )}
@@ -77,7 +77,7 @@ export default function NotesPane({ chunk, updateChunk, allTags }) {
                 {tags.map((tag) => (
                   <span key={tag} className="inline-flex items-center gap-1 rounded-full bg-[var(--r-bar)] px-2.5 py-1 text-xs">
                     {tag}
-                    <button type="button" aria-label={`Remove tag ${tag}`} onClick={() => updateChunk(chunk.id, { tags: tags.filter((t) => t !== tag) })} className="text-[var(--r-sub)] hover:text-red-600">×</button>
+                    <button type="button" aria-label={`Remove tag ${tag}`} onClick={() => updateChunk(chunk.id, { tags: tags.filter((t) => t !== tag) })} className="text-[var(--r-sub)] hover:text-[var(--r-danger,#b42318)]">×</button>
                   </span>
                 ))}
                 <input value={tagInput} onChange={(e) => setTagInput(e.target.value)} list="study-tag-suggestions"