diff --git a/frontend/src/components/Navbar.jsx b/frontend/src/components/Navbar.jsx
index 41632b4..1397672 100644
--- a/frontend/src/components/Navbar.jsx
+++ b/frontend/src/components/Navbar.jsx
@@ -166,12 +166,10 @@ function AccountMenu({ user, onLogout }) {
           <Link role="menuitem" to="/" onClick={() => setOpen(false)}>Dashboard</Link>
           {/* Settings opens on the account, so a separate Account entry was
               two doors to the same room. */}
+          {/* One door. Settings already shows the site sections to an
+              administrator, so a second entry pointing into the same page was
+              two names for one place. */}
           <Link role="menuitem" to="/settings" onClick={() => setOpen(false)}>Settings</Link>
-          {user?.role === 'admin' && (
-            <Link role="menuitem" to="/settings?s=people" onClick={() => setOpen(false)}>
-              Administration
-            </Link>
-          )}
           <button type="button" role="menuitem" className="acct-signout"
             onClick={() => { setOpen(false); onLogout() }}>Sign out</button>
         </div>
diff --git a/frontend/src/pages/AccessPage.css b/frontend/src/pages/AccessPage.css
index 65f9a34..3f90a60 100644
--- a/frontend/src/pages/AccessPage.css
+++ b/frontend/src/pages/AccessPage.css
@@ -83,3 +83,27 @@
   .ac-people ul { max-height: 240px; }
   .ac-counts { display: none; }
 }
+
+/* ── Bounded branch list ───────────────────────────────────────────────
+   The category tree runs to hundreds of rows. Left to its own height it
+   pushed the image libraries and everything else off the bottom of the
+   page, so it scrolls inside itself and starts fully collapsed. */
+.ac-tree-box {
+  max-height: 380px;
+  overflow-y: auto;
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  padding: 6px 4px;
+}
+.ac-tree-box .ac-tree { margin: 0; }
+
+.ac-person-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
+.ac-reset {
+  flex: 0 0 auto;
+  font: inherit; font-size: 0.8rem; font-weight: 600;
+  color: var(--danger, #dc2626);
+  background: none; border: 1px solid var(--border); border-radius: 8px;
+  padding: 6px 12px; cursor: pointer;
+}
+.ac-reset:hover:not(:disabled) { border-color: var(--danger, #dc2626); }
+.ac-reset:disabled { opacity: .55; cursor: default; }
diff --git a/frontend/src/pages/AccessPage.jsx b/frontend/src/pages/AccessPage.jsx
index ae0fa32..6e1f333 100644
--- a/frontend/src/pages/AccessPage.jsx
+++ b/frontend/src/pages/AccessPage.jsx
@@ -27,8 +27,13 @@ function buildTree(categories) {
  * separately grantable: the grant already reaches them, and offering a
  * checkbox that changes nothing is how a permissions screen starts lying.
  */
-function Branch({ node, byParent, granted, covered, onToggle, busy, depth = 0 }) {
-  const [open, setOpen] = useState(depth === 0)
+function Branch({ node, byParent, granted, covered, onToggle, busy, depth = 0, openPath, onOpen }) {
+  // Which branch is open is held above rather than per-node: opening one has to
+  // close the one before it, and a node cannot know about its siblings. Every
+  // branch starts closed — the full tree is hundreds of rows, and scrolling
+  // past all of it to reach the next top-level subject is the thing that made
+  // this unusable.
+  const open = openPath.includes(node.id)
   const children = byParent.get(node.id) || []
   const isGranted = granted.has(node.id)
   const isCovered = !isGranted && covered.has(node.id)
@@ -39,7 +44,7 @@ function Branch({ node, byParent, granted, covered, onToggle, busy, depth = 0 })
         {children.length > 0 ? (
           <button type="button" className="ac-twisty" aria-expanded={open}
             aria-label={`${open ? 'Collapse' : 'Expand'} ${node.name}`}
-            onClick={() => setOpen(v => !v)}>{open ? '▾' : '▸'}</button>
+            onClick={() => onOpen(node.id, depth, !open)}>{open ? '▾' : '▸'}</button>
         ) : <span className="ac-twisty" aria-hidden="true" />}
 
         <label className="ac-label">
@@ -60,7 +65,8 @@ function Branch({ node, byParent, granted, covered, onToggle, busy, depth = 0 })
         <ul>
           {children.map(child => (
             <Branch key={child.id} node={child} byParent={byParent} granted={granted}
-              covered={covered} onToggle={onToggle} busy={busy} depth={depth + 1} />
+              covered={covered} onToggle={onToggle} busy={busy} depth={depth + 1}
+              openPath={openPath} onOpen={onOpen} />
           ))}
         </ul>
       )}
@@ -85,6 +91,9 @@ export default function AccessPage() {
   const [busy, setBusy] = useState(false)
   const [error, setError] = useState('')
   const [query, setQuery] = useState('')
+  // The chain of open branches, outermost first. One per depth, so opening a
+  // subject closes the previous subject but keeps its own ancestors open.
+  const [openPath, setOpenPath] = useState([])
 
   const load = useCallback(() => {
     Promise.all([api.get('/access/'), api.get('/access/tree')])
@@ -138,6 +147,22 @@ export default function AccessPage() {
   const setRole = (role) => change(
     () => api.put(`/access/${selectedId}/role`, { role }), 'Could not change that')
 
+  const openBranch = (id, depth, on) => setOpenPath(path =>
+    on ? [...path.slice(0, depth), id] : path.slice(0, depth))
+
+  // Start this person again from nothing. Everything granted goes, including
+  // the branches reached by a parent, because removing the parent removes them.
+  const resetPerson = () => change(async () => {
+    for (const id of selected?.categories || []) {
+      await api.delete(`/access/${selectedId}/grants/category/${id}`)
+    }
+    for (const id of selected?.libraries || []) {
+      await api.delete(`/access/${selectedId}/grants/library/${id}`)
+    }
+    if (selected?.everything) await api.put(`/access/${selectedId}/role`, { role: 'user' })
+    setOpenPath([])
+  }, 'Could not clear that')
+
   if (loading) return <div className="loading"><div className="spinner" /></div>
 
   return (
@@ -146,9 +171,9 @@ export default function AccessPage() {
         <div>
           <h1>Access</h1>
           <p>
-            What each person may edit. A branch covers everything beneath it — its
-            questions and the articles filed under them — and image libraries are
-            granted one at a time.
+            Pick someone to see what they can edit. Granting a subject also grants
+            everything filed under it — its sub-topics, their questions and their
+            articles. Image libraries are granted one by one.
           </p>
         </div>
         <Link className="btn btn-secondary btn-sm" to="/settings?s=admin">Back to settings</Link>
@@ -165,7 +190,7 @@ export default function AccessPage() {
               <li key={row.id}>
                 <button type="button" className={row.id === selectedId ? 'is-active' : undefined}
                   aria-current={row.id === selectedId ? 'true' : undefined}
-                  onClick={() => setSelectedId(row.id)}>
+                  onClick={() => { setSelectedId(row.id); setOpenPath([]) }}>
                   <span className="ac-person-name">{row.name}</span>
                   <span className="ac-person-meta">
                     {row.everything ? 'Everything'
@@ -187,8 +212,16 @@ export default function AccessPage() {
           ) : (
             <>
               <div className="ac-person-head">
-                <h2>{selected.name}</h2>
-                <span>{selected.email}</span>
+                <div>
+                  <h2>{selected.name}</h2>
+                  <span>{selected.email}</span>
+                </div>
+                {(selected.everything || selected.categories.length || selected.libraries.length) > 0 &&
+                  selected.role !== 'admin' && selected.id !== me?.id && (
+                  <button type="button" className="ac-reset" disabled={busy} onClick={resetPerson}>
+                    Clear all access
+                  </button>
+                )}
               </div>
 
               {selected.role === 'admin' ? (
@@ -226,13 +259,17 @@ export default function AccessPage() {
                       )}
                     </h3>
                     {roots.length === 0 ? <p className="ac-empty">No categories yet.</p> : (
-                      <ul className="ac-tree">
-                        {roots.map(node => (
-                          <Branch key={node.id} node={node} byParent={byParent} granted={granted}
-                            covered={covered} busy={busy}
-                            onToggle={(id, on) => toggleGrant('category', id, on)} />
-                        ))}
-                      </ul>
+                      /* Bounded: the whole tree is longer than any screen, and
+                         a list that pushes the page down cannot be scanned. */
+                      <div className="ac-tree-box">
+                        <ul className="ac-tree">
+                          {roots.map(node => (
+                            <Branch key={node.id} node={node} byParent={byParent} granted={granted}
+                              covered={covered} busy={busy} openPath={openPath} onOpen={openBranch}
+                              onToggle={(id, on) => toggleGrant('category', id, on)} />
+                          ))}
+                        </ul>
+                      </div>
                     )}
                   </section>
 
diff --git a/frontend/src/pages/AccessPage.test.jsx b/frontend/src/pages/AccessPage.test.jsx
index c9c259b..b7a5e1e 100644
--- a/frontend/src/pages/AccessPage.test.jsx
+++ b/frontend/src/pages/AccessPage.test.jsx
@@ -13,6 +13,10 @@ const TREE = {
     { id: 1, name: 'Cardiology', parent_id: null, questions: 0, articles: 1 },
     { id: 2, name: 'Kawasaki disease', parent_id: 1, questions: 40, articles: 1 },
     { id: 3, name: 'Neurology', parent_id: null, questions: 12, articles: 0 },
+    // A second branch with a child of its own, so the accordion has two
+    // subjects to swap between.
+    { id: 4, name: 'Dermatology', parent_id: null, questions: 0, articles: 0 },
+    { id: 6, name: 'Eczema', parent_id: 4, questions: 8, articles: 0 },
   ],
   libraries: [{ id: 1, name: 'Rashes', assets: 30 }],
 }
@@ -59,10 +63,32 @@ describe('access', () => {
       '/access/5/grants', { kind: 'category', target_id: 1 }))
   })
 
+  it('starts every branch collapsed, so the list can be scanned', async () => {
+    mock(users({ categories: [] }))
+    mount()
+    await pick('Ada')
+    // The tree runs to hundreds of rows. Opened by default it buried the image
+    // libraries and everything under it.
+    expect(screen.getByRole('checkbox', { name: 'Grant Cardiology' })).toBeInTheDocument()
+    expect(screen.queryByRole('checkbox', { name: 'Grant Kawasaki disease' })).toBeNull()
+  })
+
+  it('opening one branch closes the one before it', async () => {
+    mock(users({ categories: [] }))
+    mount()
+    await pick('Ada')
+    await userEvent.click(screen.getByRole('button', { name: /Expand Cardiology/ }))
+    expect(screen.getByRole('checkbox', { name: 'Grant Kawasaki disease' })).toBeInTheDocument()
+    // A second subject takes the first one's place rather than adding to it.
+    await userEvent.click(screen.getByRole('button', { name: /Expand Dermatology/ }))
+    expect(screen.queryByRole('checkbox', { name: 'Grant Kawasaki disease' })).toBeNull()
+  })
+
   it('shows a child as covered by its parent, and will not let it be ticked separately', async () => {
     mock(users({ categories: [1], categories_covered: 2 }))
     mount()
     await pick('Ada')
+    await userEvent.click(screen.getByRole('button', { name: /Expand Cardiology/ }))
     const child = screen.getByRole('checkbox', { name: 'Grant Kawasaki disease' })
     expect(child).toBeChecked()
     expect(child).toBeDisabled()
diff --git a/frontend/src/pages/AdminPage.jsx b/frontend/src/pages/AdminPage.jsx
index 3013003..5ed2215 100644
--- a/frontend/src/pages/AdminPage.jsx
+++ b/frontend/src/pages/AdminPage.jsx
@@ -61,8 +61,6 @@ export default function AdminPage({ section, embedded = false }) {
   const [originalEmbedModel, setOriginalEmbedModel] = useState(null)
   const [embedModelChanged, setEmbedModelChanged] = useState(false)
   const [regenLoading, setRegenLoading] = useState(false)
-  const [classificationSnapshots, setClassificationSnapshots] = useState([])
-  const [rollbackLoading, setRollbackLoading] = useState(null)
 
   useEffect(() => {
     if (!user?.role || user.role !== 'admin') { navigate('/'); return }
@@ -72,16 +70,14 @@ export default function AdminPage({ section, embedded = false }) {
   const loadData = async (showSpinner = true) => {
     if (showSpinner) setLoading(true)
     try {
-      const [usersRes, modelsRes, settingsRes, snapshotsRes] = await Promise.all([
+      const [usersRes, modelsRes, settingsRes] = await Promise.all([
         api.get('/admin/users'),
         api.get('/admin/models'),
         api.get('/admin/settings'),
-        api.get('/admin/classification-snapshots'),
       ])
       setUsers(usersRes.data)
       setModels(modelsRes.data)
       setSettings(settingsRes.data)
-      setClassificationSnapshots(snapshotsRes.data)
       setOriginalEmbedModel(settingsRes.data.embedding_model || '')
     } catch (err) {
       setError(err.response?.data?.detail || 'Failed to load data')
@@ -250,28 +246,6 @@ export default function AdminPage({ section, embedded = false }) {
     }
   }
 
-  const rollbackClassificationSnapshot = async (snapshot) => {
-    const when = snapshot.created_at ? new Date(snapshot.created_at).toLocaleString() : `snapshot #${snapshot.id}`
-    const ok = await openConfirm(
-      `Rollback question tag assignments to snapshot #${snapshot.id} from ${when}? This replaces all current AI classification tag assignments.`,
-      { title: 'Rollback Classification', confirmLabel: 'Rollback', danger: true },
-    )
-    if (!ok) return
-
-    setRollbackLoading(snapshot.id)
-    setError('')
-    try {
-      const res = await api.post(`/admin/classification-snapshots/${snapshot.id}/rollback`)
-      setSuccess(`Restored ${res.data.restored_links} tag assignments from snapshot #${snapshot.id}`)
-      const snapshotsRes = await api.get('/admin/classification-snapshots')
-      setClassificationSnapshots(snapshotsRes.data)
-    } catch (err) {
-      setError(err.response?.data?.detail || 'Failed to roll back classification snapshot')
-    } finally {
-      setRollbackLoading(null)
-    }
-  }
-
   const addFromSearch = (modelId) => {
     setNewModel(m => ({ ...m, model_id: modelId, name: modelId, task: searchTaskHint }))
     setSearchResults([])
@@ -335,7 +309,6 @@ export default function AdminPage({ section, embedded = false }) {
   const adminTabs = [
     { id: 'models', label: 'AI Models' },
     { id: 'users', label: 'Users' },
-    { id: 'safety', label: 'Safety' },
     { id: 'settings', label: 'More' },
   ]
 
@@ -659,136 +632,11 @@ export default function AdminPage({ section, embedded = false }) {
         </>
       )}
 
-      {tab === 'safety' && (
-        <div className="card">
-          <h2>Classification Rollback</h2>
-          <p style={{ color: 'var(--text-muted)', fontSize: '0.85rem', marginBottom: 16 }}>
-            Every AI classification run saves the current question tag assignments before it starts. Use this if a classification run adds bad subjects, diseases, or keywords.
-          </p>
-
-          {classificationSnapshots.length === 0 ? (
-            <div style={{ color: 'var(--text-muted)', fontSize: '0.9rem' }}>
-              No classification snapshots have been saved yet.
-            </div>
-          ) : (
-            <div style={{ display: 'grid', gap: 10 }}>
-              {classificationSnapshots.map(snapshot => (
-                <div key={snapshot.id} style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', gap: 12, padding: 12, border: '1px solid var(--border)', borderRadius: 8 }}>
-                  <div>
-                    <strong style={{ display: 'block', marginBottom: 4 }}>Snapshot #{snapshot.id}</strong>
-                    <div style={{ fontSize: '0.82rem', color: 'var(--text-muted)' }}>
-                      {snapshot.created_at ? new Date(snapshot.created_at).toLocaleString() : 'Unknown date'} · {snapshot.question_count} tagged questions · {snapshot.link_count} tag assignments
-                    </div>
-                    {snapshot.created_by_email && (
-                      <div style={{ fontSize: '0.78rem', color: 'var(--text-muted)', marginTop: 2 }}>
-                        Created by {snapshot.created_by_name || snapshot.created_by_email}
-                      </div>
-                    )}
-                  </div>
-                  <button
-                    className="btn btn-danger btn-sm"
-                    onClick={() => rollbackClassificationSnapshot(snapshot)}
-                    disabled={rollbackLoading === snapshot.id}
-                  >
-                    {rollbackLoading === snapshot.id ? 'Rolling back...' : 'Rollback'}
-                  </button>
-                </div>
-              ))}
-            </div>
-          )}
-        </div>
-      )}
-
       {tab === 'settings' && (
         <div className="card">
-          <h2>More Settings</h2>
+          <h2>Semantic search</h2>
           <div style={{ marginTop: 16 }}>
 
-            {/* Public Registration */}
-            <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '12px 0', borderBottom: '1px solid var(--border)' }}>
-              <div>
-                <strong style={{ display: 'block', marginBottom: 4 }}>Public Registration</strong>
-                <span style={{ fontSize: '0.85rem', color: 'var(--text-muted)' }}>
-                  Allow new users to create accounts. Admins can always create users manually.
-                </span>
-              </div>
-              <label style={{ display: 'flex', alignItems: 'center', gap: 8, cursor: 'pointer' }}>
-                <input
-                  type="checkbox"
-                  checked={settings.registration_enabled}
-                  onChange={async (e) => {
-                    const enabled = e.target.checked
-                    setSettings(s => ({ ...s, registration_enabled: enabled }))
-                    try {
-                      await api.put('/admin/settings', { registration_enabled: enabled })
-                      setSuccess(`Registration ${enabled ? 'enabled' : 'disabled'}`)
-                    } catch (err) {
-                      setError(err.response?.data?.detail || 'Failed to update setting')
-                      setSettings(s => ({ ...s, registration_enabled: !enabled }))
-                    }
-                  }}
-                  style={{ width: 'auto', accentColor: 'var(--primary)' }}
-                />
-                <span style={{ fontSize: '0.9rem', fontWeight: 600 }}>
-                  {settings.registration_enabled ? 'Enabled' : 'Disabled'}
-                </span>
-              </label>
-            </div>
-
-            {/* SSO Only */}
-            {settings.sso_configured && (
-              <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '12px 0', borderBottom: '1px solid var(--border)' }}>
-                <div>
-                  <strong style={{ display: 'block', marginBottom: 4 }}>SSO-Only Login ({settings.sso_provider_name})</strong>
-                  <span style={{ fontSize: '0.85rem', color: 'var(--text-muted)' }}>
-                    Disable password login — users must sign in via SSO. Admins can still use CLI to reset passwords.
-                  </span>
-                </div>
-                <label style={{ display: 'flex', alignItems: 'center', gap: 8, cursor: 'pointer' }}>
-                  <input
-                    type="checkbox"
-                    checked={settings.sso_only || false}
-                    onChange={async (e) => {
-                      const enabled = e.target.checked
-                      setSettings(s => ({ ...s, sso_only: enabled }))
-                      try {
-                        await api.put('/admin/settings', { sso_only: enabled })
-                        setSuccess(`SSO-only mode ${enabled ? 'enabled' : 'disabled'}`)
-                      } catch (err) {
-                        setError(err.response?.data?.detail || 'Failed to update setting')
-                        setSettings(s => ({ ...s, sso_only: !enabled }))
-                      }
-                    }}
-                    style={{ width: 'auto', accentColor: 'var(--primary)' }}
-                  />
-                  <span style={{ fontSize: '0.9rem', fontWeight: 600 }}>
-                    {settings.sso_only ? 'Enabled' : 'Disabled'}
-                  </span>
-                </label>
-              </div>
-            )}
-
-            {/* Embedding model change warning */}
-            {embedModelChanged && (
-              <div style={{ padding: '12px 16px', background: '#fef3c7', border: '1px solid #f59e0b', borderRadius: 8, marginBottom: 0, marginTop: 8 }}>
-                <strong style={{ color: '#92400e', display: 'block', marginBottom: 6 }}>
-                  ⚠️ Embedding model changed
-                </strong>
-                <span style={{ fontSize: '0.85rem', color: '#78350f' }}>
-                  Existing question embeddings were generated with the previous model and may produce inaccurate semantic search results.
-                  Regenerate them to restore full search quality.
-                </span>
-                <div style={{ marginTop: 10 }}>
-                  <button className="btn btn-primary btn-sm" onClick={startRegeneration} disabled={regenLoading}>
-                    {regenLoading ? 'Starting…' : 'Regenerate All Embeddings'}
-                  </button>
-                  <button className="btn btn-secondary btn-sm" style={{ marginLeft: 8 }} onClick={() => setEmbedModelChanged(false)}>
-                    Dismiss
-                  </button>
-                </div>
-              </div>
-            )}
-
             {/* Embedding Model */}
             <div style={{ padding: '16px 0' }}>
               <strong style={{ display: 'block', marginBottom: 4 }}>Embedding Model</strong>
diff --git a/frontend/src/pages/SettingsPage.jsx b/frontend/src/pages/SettingsPage.jsx
index 5314993..4b64b2f 100644
--- a/frontend/src/pages/SettingsPage.jsx
+++ b/frontend/src/pages/SettingsPage.jsx
@@ -451,12 +451,9 @@ export default function SettingsPage() {
       { key: 'models', group: 'The site', icon: '🧠', label: 'AI models',
         render: () => <AdminSection section="models" title="AI models"
           description="Which model answers which kind of request, and what happens when one is unavailable." /> },
-      { key: 'safety', group: 'The site', icon: '🛡️', label: 'Safety',
-        render: () => <AdminSection section="safety" title="Safety"
-          description="Limits on what the assistant will do, and what it refuses." /> },
       { key: 'search', group: 'The site', icon: '🔎', label: 'Search',
-        render: () => <AdminSection section="settings" title="Search and sign-up"
-          description="The embedding model behind semantic search, and how accounts are created." /> },
+        render: () => <AdminSection section="settings" title="Search"
+          description="The embedding model behind semantic search." /> },
     ] : []),
   ]
 
diff --git a/frontend/src/pages/SettingsPage.test.jsx b/frontend/src/pages/SettingsPage.test.jsx
index 78eee8a..c5a7a36 100644
--- a/frontend/src/pages/SettingsPage.test.jsx
+++ b/frontend/src/pages/SettingsPage.test.jsx
@@ -73,10 +73,14 @@ describe('settings', () => {
     await screen.findByRole('heading', { name: 'Account' })
     // The old page offered a grid of links, one of which went to /admin and
     // its own row of tabs. These are sections of this page now.
-    for (const label of ['People', 'AI models', 'Safety', 'Search']) {
+    for (const label of ['People', 'AI models', 'Search']) {
       expect(screen.getByRole('button', { name: new RegExp(label) })).toBeInTheDocument()
     }
     expect(screen.queryByRole('link', { name: /Admin dashboard/ })).toBeNull()
+    // Safety held one thing: rolling back AI classification tag assignments.
+    // The classifier is gone, so the section had nothing left to be about, and
+    // permissions — the other thing it might have held — are on Access.
+    expect(screen.queryByRole('button', { name: /Safety/ })).toBeNull()
   })
 
   it('carries the exam objective, which was only reachable from the navbar', async () => {