diff --git a/server.js b/server.js
index 4ef970b..3687e77 100644
--- a/server.js
+++ b/server.js
@@ -17,6 +17,56 @@ types.setTypeParser(1082, v => v);
 const app = express();
 const pool = new Pool({ connectionString: process.env.DATABASE_URL });
 
+const cacheStore = new Map();
+const SETTINGS_TTL_MS = 30 * 1000;
+const PUBLIC_TTL_MS = 60 * 1000;
+const SHARE_TTL_MS = 60 * 1000;
+const STATS_TTL_MS = 15 * 1000;
+const SYSTEM_TTL_MS = 30 * 1000;
+
+function cacheGet(key) {
+  const entry = cacheStore.get(key);
+  if (!entry) return undefined;
+  if (entry.exp && entry.exp <= Date.now()) {
+    cacheStore.delete(key);
+    return undefined;
+  }
+  return entry.value;
+}
+
+function cacheSet(key, value, ttlMs) {
+  cacheStore.set(key, { value, exp: ttlMs ? Date.now() + ttlMs : 0 });
+}
+
+function cacheDrop(prefix) {
+  for (const key of cacheStore.keys()) {
+    if (key.startsWith(prefix)) cacheStore.delete(key);
+  }
+}
+
+async function cacheWrap(key, ttlMs, fn) {
+  const hit = cacheGet(key);
+  if (hit !== undefined) return hit;
+  const value = await fn();
+  cacheSet(key, value, ttlMs);
+  return value;
+}
+
+function scopeKey(user) {
+  if (!user) return 'anon';
+  const s = branchScope(user);
+  if (s.admin) return 'all';
+  return s.ids.length ? s.ids.slice().sort((a, b) => a - b).join('-') : 'none';
+}
+
+function invalidateSettings() { cacheDrop('setting:'); cacheDrop('share:payload:'); cacheDrop('public-settings'); }
+function invalidateStudents() { cacheDrop('students:'); }
+function invalidateGroups() { cacheDrop('groups:'); cacheDrop('students:'); cacheDrop('share:payload:'); }
+function invalidateEntries() { cacheDrop('entries:'); cacheDrop('students:'); cacheDrop('share:payload:'); }
+function invalidateShare() { cacheDrop('share:payload:'); }
+function invalidateStats() { cacheDrop('stats:'); cacheDrop('dashboard:'); cacheDrop('system-info'); }
+function invalidateAll() { cacheStore.clear(); }
+
 const apiLimiter = rateLimit({
   windowMs: 15 * 60 * 1000,
   max: 300,
@@ -64,8 +114,9 @@ app.use(helmet({
   }
 }));
 app.use(express.json({ limit: '1mb' }));
-app.use('/uploads', express.static(path.join(__dirname, 'uploads')));
-app.use(express.static(path.join(__dirname, 'public')));
+app.use('/uploads', express.static(path.join(__dirname, 'uploads'), { maxAge: '365d', immutable: true }));
+app.use('/vendor', express.static(path.join(__dirname, 'public', 'vendor'), { maxAge: '30d' }));
+app.use(express.static(path.join(__dirname, 'public'), { maxAge: '1h' }));
 
 const SESSION_TTL_MS = 30 * 24 * 60 * 60 * 1000;
 
@@ -294,8 +345,12 @@ const adminUpload = multer({
 });
 
 async function getSetting(key, def) {
+  const cached = cacheGet('setting:' + key);
+  if (cached !== undefined) return cached;
   const { rows } = await pool.query('SELECT value FROM settings WHERE key = $1', [key]);
-  return rows.length ? rows[0].value : def;
+  const value = rows.length ? rows[0].value : def;
+  cacheSet('setting:' + key, value, SETTINGS_TTL_MS);
+  return value;
 }
 
 const UPLOADS_DIR = path.join(__dirname, 'uploads');
@@ -656,9 +711,12 @@ app.get('/api/settings', requireAdmin, async (_, res) => {
 });
 
 app.get('/api/public-settings', apiLimiter, async (_, res) => {
-  const keys = ['footer_left', 'footer_right', 'share_show_student_message', 'share_show_entry_date', 'share_show_student_names', 'share_show_group_photos'];
-  const out = {};
-  for (const k of keys) out[k] = await getSetting(k, '');
+  const out = await cacheWrap('public-settings', PUBLIC_TTL_MS, async () => {
+    const keys = ['footer_left', 'footer_right', 'share_show_student_message', 'share_show_entry_date', 'share_show_student_names', 'share_show_group_photos'];
+    const result = {};
+    for (const k of keys) result[k] = await getSetting(k, '');
+    return result;
+  });
   res.json(out);
 });
 
@@ -685,6 +743,7 @@ app.put('/api/settings', requireAdmin, async (req, res) => {
     }
     await client.query('COMMIT');
     await logAudit(req, 'settings.update', { settings });
+    invalidateSettings();
     const { rows } = await pool.query('SELECT key, value FROM settings ORDER BY key');
     const out = {};
     rows.forEach(r => { out[r.key] = r.value; });
@@ -1163,6 +1222,7 @@ app.post('/api/restore', requireAdmin, uploadBackup.single('backup'), async (req
   await sweepOrphanedUploads().catch(err => console.error('Upload sweep:', err));
   await ensureFirstAdmin().catch(err => console.error('First admin:', err));
   await logAudit(req, 'backup.restore', {});
+  invalidateAll();
   res.json({ ok: true });
 });
 
@@ -1246,6 +1306,7 @@ app.post('/api/links', requireAuth, async (req, res) => {
     [token, name.trim(), group_id || null, student_name || null, date_from || null, date_to || null, req.body.show_student_names == null ? null : !!req.body.show_student_names, expiresAt, passwordHash, message, linkUrl, req.body.show_student_message == null ? null : !!req.body.show_student_message, req.body.show_entry_date == null ? null : !!req.body.show_entry_date, req.body.show_group_photos == null ? null : !!req.body.show_group_photos]
   );
   await logAudit(req, 'link.create', { id: rows[0].id, name: name.trim() });
+  invalidateShare();
   res.status(201).json(normDates(rows[0]));
 });
 
@@ -1308,6 +1369,7 @@ app.put('/api/links/:id', requireAuth, async (req, res) => {
   );
   if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
   await logAudit(req, 'link.update', { id: req.params.id, name: name.trim() });
+  invalidateShare();
   res.json(normDates(rows[0]));
 });
 
@@ -1321,6 +1383,7 @@ app.delete('/api/links/:id', requireAuth, async (req, res) => {
   }
   await pool.query('DELETE FROM share_links WHERE id = $1', [req.params.id]);
   await logAudit(req, 'link.delete', { id: req.params.id });
+  invalidateShare();
   res.json({ ok: true });
 });
 
@@ -1351,70 +1414,72 @@ app.get('/api/share/:token', fileLimiter, async (req, res) => {
     }
   }
 
-  const conditions = [];
-  const params = [];
-  if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
-  if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
-  if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
-  if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
-  conditions.push('e.deleted_at IS NULL');
-  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
-  const { rows: entries } = await pool.query(
-    `SELECT e.*, g.name AS group_name FROM entries e
-     JOIN groups g ON g.id = e.group_id${where} ORDER BY e.created_at DESC`,
-    params
-  );
-  let files = {};
-  if (entries.length) {
-    const fRes = await pool.query(
-      'SELECT entry_id, token, name FROM project_files WHERE entry_id = ANY($1) ORDER BY id',
-      [entries.map(r => r.id)]
+  const payload = await cacheWrap('share:payload:' + req.params.token, SHARE_TTL_MS, async () => {
+    const conditions = [];
+    const params = [];
+    if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
+    if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
+    if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
+    if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
+    conditions.push('e.deleted_at IS NULL');
+    const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
+    const { rows: entries } = await pool.query(
+      `SELECT e.*, g.name AS group_name FROM entries e
+       JOIN groups g ON g.id = e.group_id${where} ORDER BY e.created_at DESC`,
+      params
     );
-    fRes.rows.forEach(f => { (files[f.entry_id] = files[f.entry_id] || []).push({ token: f.token, name: f.name }); });
-  }
-  entries.forEach(r => { r.files = files[r.id] || []; });
+    let files = {};
+    if (entries.length) {
+      const fRes = await pool.query(
+        'SELECT entry_id, token, name FROM project_files WHERE entry_id = ANY($1) ORDER BY id',
+        [entries.map(r => r.id)]
+      );
+      fRes.rows.forEach(f => { (files[f.entry_id] = files[f.entry_id] || []).push({ token: f.token, name: f.name }); });
+    }
+    entries.forEach(r => { r.files = files[r.id] || []; });
 
-  const showStudentNames = l.show_student_names != null ? l.show_student_names : (await getSetting('share_show_student_names', 'true')) !== 'false';
+    const showStudentNames = l.show_student_names != null ? l.show_student_names : (await getSetting('share_show_student_names', 'true')) !== 'false';
 
-  // Anonymize names if disabled
-  if (!showStudentNames) {
-    const nameMap = new Map();
-    let counter = 1;
-    entries.forEach(e => {
-      if (!nameMap.has(e.student_name)) {
-        nameMap.set(e.student_name, `Ученик ${counter++}`);
-      }
-      e.student_name = nameMap.get(e.student_name);
-    });
-  }
+    if (!showStudentNames) {
+      const nameMap = new Map();
+      let counter = 1;
+      entries.forEach(e => {
+        if (!nameMap.has(e.student_name)) {
+          nameMap.set(e.student_name, `Ученик ${counter++}`);
+        }
+        e.student_name = nameMap.get(e.student_name);
+      });
+    }
 
-  let photos = [];
-  if (l.group_id) {
-    const pRes = await pool.query(
-      `SELECT id, photo_path, caption, taken_at, created_at FROM group_photos
-       WHERE group_id = $1 ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC LIMIT 12`,
-      [l.group_id]
-    );
-    photos = pRes.rows.map(r => ({ id: r.id, photo_path: r.photo_path, caption: r.caption, taken_at: r.taken_at, created_at: r.created_at }));
-  }
-  res.json({
-    name: l.name,
-    group_name: l.group_name,
-    student_name: l.student_name,
-    group_id: l.group_id,
-    date_from: l.date_from,
-    date_to: l.date_to,
-    message: l.message,
-    link_url: l.link_url,
-    created_at: l.created_at,
-    expires_at: l.expires_at,
-    show_student_names: showStudentNames,
-    show_student_message: l.show_student_message != null ? l.show_student_message : (await getSetting('share_show_student_message', 'false')) === 'true',
-    show_entry_date: l.show_entry_date != null ? l.show_entry_date : (await getSetting('share_show_entry_date', 'false')) === 'true',
-    show_group_photos: l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false',
-    entries,
-    photos: (l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false') ? photos : [],
+    let photos = [];
+    if (l.group_id) {
+      const pRes = await pool.query(
+        `SELECT id, photo_path, caption, taken_at, created_at FROM group_photos
+         WHERE group_id = $1 ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC LIMIT 12`,
+        [l.group_id]
+      );
+      photos = pRes.rows.map(r => ({ id: r.id, photo_path: r.photo_path, caption: r.caption, taken_at: r.taken_at, created_at: r.created_at }));
+    }
+    return {
+      name: l.name,
+      group_name: l.group_name,
+      student_name: l.student_name,
+      group_id: l.group_id,
+      date_from: l.date_from,
+      date_to: l.date_to,
+      message: l.message,
+      link_url: l.link_url,
+      created_at: l.created_at,
+      expires_at: l.expires_at,
+      show_student_names: showStudentNames,
+      show_student_message: l.show_student_message != null ? l.show_student_message : (await getSetting('share_show_student_message', 'false')) === 'true',
+      show_entry_date: l.show_entry_date != null ? l.show_entry_date : (await getSetting('share_show_entry_date', 'false')) === 'true',
+      show_group_photos: l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false',
+      entries,
+      photos: (l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false') ? photos : [],
+    };
   });
+  res.json(payload);
 });
 
 app.get('/api/share/:shareToken/files/:fileToken', fileLimiter, async (req, res) => {
@@ -1460,34 +1525,40 @@ app.get('/s/:token', (req, res) => {
 
 // --- Groups CRUD ---
 app.get('/api/groups', apiLimiter, optionalAuth, async (req, res) => {
-  const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
-  const { rows } = await pool.query(
-    `SELECT g.*,
-       COALESCE(g.cover_path,
-         (SELECT photo_path FROM group_photos
-          WHERE group_id = g.id
-          ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC
-          LIMIT 1)) AS cover_path,
-       b.name AS branch_name
-     FROM groups g
-     LEFT JOIN branches b ON b.id = g.branch_id
-     WHERE 1=1${bw.where}
-     ORDER BY g.id`,
-    bw.params
-  );
+  const rows = await cacheWrap('groups:list:' + scopeKey(req.user), PUBLIC_TTL_MS, async () => {
+    const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
+    const { rows } = await pool.query(
+      `SELECT g.*,
+         COALESCE(g.cover_path,
+           (SELECT photo_path FROM group_photos
+            WHERE group_id = g.id
+            ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC
+            LIMIT 1)) AS cover_path,
+         b.name AS branch_name
+       FROM groups g
+       LEFT JOIN branches b ON b.id = g.branch_id
+       WHERE 1=1${bw.where}
+       ORDER BY g.id`,
+      bw.params
+    );
+    return rows;
+  });
   res.json(rows);
 });
 
 app.get('/api/groups/active', apiLimiter, async (_, res) => {
-  const { rows } = await pool.query(`
-    SELECT * FROM groups
-    WHERE day_of_week IS NOT NULL
-      AND time_start IS NOT NULL
-      AND time_end IS NOT NULL
-      AND day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
-      AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN time_start AND time_end
-    ORDER BY id
-  `);
+  const rows = await cacheWrap('groups:active', PUBLIC_TTL_MS, async () => {
+    const { rows } = await pool.query(`
+      SELECT * FROM groups
+      WHERE day_of_week IS NOT NULL
+        AND time_start IS NOT NULL
+        AND time_end IS NOT NULL
+        AND day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
+        AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN time_start AND time_end
+      ORDER BY id
+    `);
+    return rows;
+  });
   res.json(rows);
 });
 
@@ -1516,6 +1587,8 @@ app.put('/api/groups/:id', requireAuth, async (req, res) => {
        req.params.id]
     );
     await logAudit(req, 'group.update', { id: req.params.id, ...req.body });
+    invalidateGroups();
+    invalidateStats();
     res.json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Duplicate name' });
@@ -1537,6 +1610,8 @@ app.post('/api/groups', requireAuth, async (req, res) => {
       [name.trim(), isAdmin ? effectiveBranch : null]
     );
     await logAudit(req, 'group.create', { id: rows[0].id, name: name.trim(), branch_id });
+    invalidateGroups();
+    invalidateStats();
     res.status(201).json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
@@ -1555,6 +1630,8 @@ app.delete('/api/groups/:id', requireAuth, async (req, res) => {
   rows.forEach(r => safeUnlink(r.photo_path));
   await pool.query('DELETE FROM groups WHERE id = $1', [req.params.id]);
   await logAudit(req, 'group.delete', { id: req.params.id });
+  invalidateGroups();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -1591,6 +1668,7 @@ app.post('/api/branches', requireAdmin, async (req, res) => {
       [name.trim(), address?.trim() || null, phone?.trim() || null]
     );
     await logAudit(req, 'branch.create', { id: rows[0].id, name: name.trim() });
+    invalidateGroups();
     res.status(201).json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Филиал с таким названием уже существует' });
@@ -1612,6 +1690,7 @@ app.put('/api/branches/:id', requireAdmin, async (req, res) => {
     );
     if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
     await logAudit(req, 'branch.update', { id: req.params.id, ...req.body });
+    invalidateGroups();
     res.json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Филиал с таким названием уже существует' });
@@ -1624,6 +1703,7 @@ app.delete('/api/branches/:id', requireAdmin, async (req, res) => {
   if (rows.length) return res.status(400).json({ error: 'Нельзя удалить филиал: есть привязанные группы' });
   await pool.query('DELETE FROM branches WHERE id = $1', [req.params.id]);
   await logAudit(req, 'branch.delete', { id: req.params.id });
+  invalidateGroups();
   res.json({ ok: true });
 });
 
@@ -1681,6 +1761,9 @@ app.post('/api/groups/:id/photos', requireAuth, (req, res, next) => {
       [req.params.id, `/uploads/${req.file.filename}`, caption?.trim() || null, taken_at || null]
     );
     await logAudit(req, 'group.photo.create', { group_id: req.params.id, photo_path: rows[0].photo_path });
+    invalidateShare();
+    invalidateGroups();
+    invalidateStats();
     res.status(201).json(rows[0]);
   } catch (e) {
     safeUnlink(`uploads/${req.file.filename}`);
@@ -1722,6 +1805,8 @@ app.put('/api/groups/:id/photos/reorder', requireAuth, async (req, res) => {
     }
     await client.query('COMMIT');
     await logAudit(req, 'group.photo.reorder', { group_id: req.params.id, order: ids });
+    invalidateShare();
+    invalidateGroups();
     res.json({ ok: true });
   } catch (e) {
     await client.query('ROLLBACK');
@@ -1746,6 +1831,7 @@ app.put('/api/groups/:id/photos/:photoId', requireAuth, async (req, res) => {
   );
   if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
   await logAudit(req, 'group.photo.update', { group_id: req.params.id, photo_id: req.params.photoId });
+  invalidateShare();
   res.json(rows[0]);
 });
 
@@ -1762,6 +1848,9 @@ app.delete('/api/groups/:id/photos/:photoId', requireAuth, async (req, res) => {
   await pool.query('UPDATE groups SET cover_path = NULL WHERE id = $1 AND cover_path = $2', [req.params.id, rows[0].photo_path]);
   await pool.query('DELETE FROM group_photos WHERE id = $1', [req.params.photoId]);
   await logAudit(req, 'group.photo.delete', { group_id: req.params.id, photo_id: req.params.photoId });
+  invalidateShare();
+  invalidateGroups();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -1776,19 +1865,24 @@ app.put('/api/groups/:id/photos/:photoId/cover', requireAuth, async (req, res) =
   if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
   await pool.query('UPDATE groups SET cover_path = $1 WHERE id = $2', [rows[0].photo_path, req.params.id]);
   await logAudit(req, 'group.photo.set_cover', { group_id: req.params.id, photo_id: req.params.photoId });
+  invalidateShare();
+  invalidateGroups();
   const { rows: gRows } = await pool.query('SELECT * FROM groups WHERE id = $1', [req.params.id]);
   res.json(gRows[0]);
 });
 
 // --- Students CRUD ---
 app.get('/api/students', apiLimiter, optionalAuth, async (req, res) => {
-  const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
-  const { rows } = await pool.query(
-    `SELECT s.*, g.name AS group_name FROM students s
-     LEFT JOIN groups g ON g.id = s.group_id
-     WHERE 1=1${bw.where} ORDER BY s.name`,
-    bw.params
-  );
+  const rows = await cacheWrap('students:list:' + scopeKey(req.user), PUBLIC_TTL_MS, async () => {
+    const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
+    const { rows } = await pool.query(
+      `SELECT s.*, g.name AS group_name FROM students s
+       LEFT JOIN groups g ON g.id = s.group_id
+       WHERE 1=1${bw.where} ORDER BY s.name`,
+      bw.params
+    );
+    return rows;
+  });
   res.json(rows);
 });
 
@@ -1817,6 +1911,8 @@ app.post('/api/students', requireAuth, async (req, res) => {
       [name.trim(), gid]
     );
     await logAudit(req, 'student.create', { id: rows[0].id, name: name.trim() });
+    invalidateStudents();
+    invalidateStats();
     res.status(201).json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
@@ -1852,6 +1948,7 @@ app.put('/api/students/:id', requireAuth, async (req, res) => {
     );
     if (!rows.length) return res.status(404).json({ error: 'Not found' });
     await logAudit(req, 'student.update', { id: req.params.id, name: name.trim() });
+    invalidateStudents();
     res.json(rows[0]);
   } catch (e) {
     if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
@@ -1876,6 +1973,7 @@ app.post('/api/students/batch-group', requireAuth, async (req, res) => {
     params
   );
   await logAudit(req, 'student.batch-group', { group_id, count: rows.length });
+  invalidateStudents();
   res.json({ ok: true, updated: rows.length });
 });
 
@@ -1892,6 +1990,8 @@ app.delete('/api/students/:id', requireAuth, async (req, res) => {
   }
   await pool.query('DELETE FROM students WHERE id = $1', [req.params.id]);
   await logAudit(req, 'student.delete', { id: req.params.id });
+  invalidateStudents();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2026,6 +2126,8 @@ app.post('/api/entries/:id/files', requireAuth, (req, res, next) => {
       );
     }
     await client.query('COMMIT');
+    invalidateShare();
+    invalidateEntries();
     res.status(201).json({ ok: true, count: files.length });
   } catch (e) {
     await client.query('ROLLBACK').catch(() => {});
@@ -2133,6 +2235,8 @@ app.post('/api/files/:id/detach', requireAuth, async (req, res) => {
     [req.params.id]
   );
   if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
+  invalidateShare();
+  invalidateEntries();
   res.json({ ok: true });
 });
 
@@ -2152,6 +2256,8 @@ app.delete('/api/files/:id', requireAuth, async (req, res) => {
   if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
   safeUnlink(rows[0].path);
   await pool.query('DELETE FROM project_files WHERE id = $1', [req.params.id]);
+  invalidateShare();
+  invalidateEntries();
   res.json({ ok: true });
 });
 
@@ -2166,37 +2272,41 @@ app.get('/api/files/:token', fileLimiter, async (req, res) => {
 });
 
 app.get('/api/stats', requireAuth, async (req, res) => {
-  const isAdmin = req.user.role === 'admin';
-  const s = branchScope(req.user);
-  let groupFilter;
-  if (isAdmin) {
-    groupFilter = { where: '', params: [] };
-  } else if (!s.ids.length) {
-    groupFilter = { where: ' AND 1 = 0', params: [] };
-  } else {
-    const ph = s.ids.map(id => `$${s.ids.indexOf(id) + 1}`).join(',');
-    groupFilter = { where: ` AND g.branch_id IN (${ph})`, params: s.ids };
-  }
-  const groupsParams = isAdmin ? [] : (s.ids.length ? s.ids : [0]);
-  const groupsWhere = isAdmin ? '' : (s.ids.length ? ` WHERE g.branch_id IN (${groupsParams.map((_, i) => `$${i + 1}`).join(',')})` : ' WHERE 1 = 0');
-  const [entries, trash, groups, students, today] = await Promise.all([
-    pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
-    pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NOT NULL${groupFilter.where}`, groupFilter.params),
-    pool.query(`SELECT count(*)::int AS n FROM groups g${groupsWhere}`, groupsParams),
-    pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
-    pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${groupFilter.where}`, groupFilter.params),
-  ]);
-  res.json({
-    entries: entries.rows[0].n,
-    trash: trash.rows[0].n,
-    groups: groups.rows[0].n,
-    students: students.rows[0].n,
-    today: today.rows[0].n,
+  const payload = await cacheWrap('stats:' + scopeKey(req.user), STATS_TTL_MS, async () => {
+    const isAdmin = req.user.role === 'admin';
+    const s = branchScope(req.user);
+    let groupFilter;
+    if (isAdmin) {
+      groupFilter = { where: '', params: [] };
+    } else if (!s.ids.length) {
+      groupFilter = { where: ' AND 1 = 0', params: [] };
+    } else {
+      const ph = s.ids.map(id => `$${s.ids.indexOf(id) + 1}`).join(',');
+      groupFilter = { where: ` AND g.branch_id IN (${ph})`, params: s.ids };
+    }
+    const groupsParams = isAdmin ? [] : (s.ids.length ? s.ids : [0]);
+    const groupsWhere = isAdmin ? '' : (s.ids.length ? ` WHERE g.branch_id IN (${groupsParams.map((_, i) => `$${i + 1}`).join(',')})` : ' WHERE 1 = 0');
+    const [entries, trash, groups, students, today] = await Promise.all([
+      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
+      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NOT NULL${groupFilter.where}`, groupFilter.params),
+      pool.query(`SELECT count(*)::int AS n FROM groups g${groupsWhere}`, groupsParams),
+      pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
+      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${groupFilter.where}`, groupFilter.params),
+    ]);
+    return {
+      entries: entries.rows[0].n,
+      trash: trash.rows[0].n,
+      groups: groups.rows[0].n,
+      students: students.rows[0].n,
+      today: today.rows[0].n,
+    };
   });
+  res.json(payload);
 });
 
 app.get('/api/system-info', requireAdmin, async (_, res) => {
   try {
+    const payload = await cacheWrap('system-info', SYSTEM_TTL_MS, async () => {
     const db = await pool.query(`
       SELECT 
         pg_size_pretty(pg_database_size(current_database())) AS db_size,
@@ -2264,7 +2374,7 @@ app.get('/api/system-info', requireAdmin, async (_, res) => {
 
     const diskInfo = getDiskInfo();
 
-    res.json({
+    return {
       database: {
         size: db.rows[0].db_size,
         size_bytes: parseInt(db.rows[0].db_size_bytes, 10),
@@ -2290,7 +2400,9 @@ app.get('/api/system-info', requireAdmin, async (_, res) => {
         size_bytes: uploadsSize,
       },
       disk: diskInfo,
+    };
     });
+    res.json(payload);
   } catch (e) {
     console.error('System info error:', e);
     res.status(500).json({ error: e.message });
@@ -2298,6 +2410,7 @@ app.get('/api/system-info', requireAdmin, async (_, res) => {
 });
 
 app.get('/api/dashboard', requireAuth, async (req, res) => {
+  const payload = await cacheWrap('dashboard:' + scopeKey(req.user), STATS_TTL_MS, async () => {
   const DAYS = ['Вс', 'Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб'];
   const isAdmin = req.user.role === 'admin';
   const s = branchScope(req.user);
@@ -2365,7 +2478,7 @@ app.get('/api/dashboard', requireAuth, async (req, res) => {
     time_start: (g.time_start || '').slice(0, 5),
     time_end: (g.time_end || '').slice(0, 5),
   }));
-  res.json({
+  return {
     stats: stats,
     activity: activity.rows,
     active_groups: activeGroups,
@@ -2374,7 +2487,9 @@ app.get('/api/dashboard', requireAuth, async (req, res) => {
     photos: photos.rows,
     latest_photo_taken: (latestPhotos.rows[0] || {}).taken_at || null,
     disk: getDiskInfo(),
+  };
   });
+  res.json(payload);
 });
 
 const entryFields = upload.fields([{ name: 'photo', maxCount: 10 }, { name: 'files', maxCount: 10 }]);
@@ -2462,6 +2577,8 @@ app.post('/api/entries', entryLimiter, (req, res, next) => {
     }
     await client.query('COMMIT');
     if (entryAutoChecker) entryAutoChecker.notify();
+    invalidateEntries();
+    invalidateStats();
     res.status(201).json({ ...rows[0], files: projectFiles.length, photos: photos.length });
   } catch (e) {
     await client.query('ROLLBACK').catch(() => {});
@@ -2526,6 +2643,8 @@ app.put('/api/entries/:id', requireAuth, upload.array('photo', 10), async (req,
   }
 
   await logAudit(req, 'entry.update', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json(rows[0]);
 });
 
@@ -2560,6 +2679,7 @@ app.delete('/api/entries/:id/photos/:photoId', requireAuth, async (req, res) =>
     await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [nextRows.length ? nextRows[0].photo_path : null, req.params.id]);
   }
   await logAudit(req, 'entry.photo.delete', { entry_id: req.params.id, photo_id: req.params.photoId });
+  invalidateEntries();
   res.json({ ok: true });
 });
 
@@ -2576,6 +2696,7 @@ app.put('/api/entries/:id/photos/:photoId', requireAuth, async (req, res) => {
   );
   if (!rows.length) return res.status(404).json({ error: 'Фото не найдено' });
   await logAudit(req, 'entry.photo.update', { entry_id: req.params.id, photo_id: req.params.photoId });
+  invalidateEntries();
   res.json(rows[0]);
 });
 
@@ -2589,6 +2710,7 @@ app.put('/api/entries/:id/photos/:photoId/main', requireAuth, async (req, res) =
   if (!rows.length) return res.status(404).json({ error: 'Фото не найдено' });
   await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [rows[0].photo_path, req.params.id]);
   await logAudit(req, 'entry.photo.set_main', { entry_id: req.params.id, photo_id: req.params.photoId });
+  invalidateEntries();
   res.json({ ok: true, photo_path: rows[0].photo_path });
 });
 
@@ -2600,6 +2722,8 @@ app.delete('/api/entries/:id', requireAuth, async (req, res) => {
   }
   await pool.query('UPDATE entries SET deleted_at = now() WHERE id = $1', [req.params.id]);
   await logAudit(req, 'entry.soft-delete', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2618,6 +2742,8 @@ app.put('/api/entries/:id/restore', requireAuth, async (req, res) => {
     return res.status(404).json({ error: 'Запись не найдена или уже восстановлена' });
   }
   await logAudit(req, 'entry.restore', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2633,6 +2759,8 @@ app.delete('/api/entries/:id/permanent', requireAuth, async (req, res) => {
   await removeEntryFiles(req.params.id);
   await pool.query('DELETE FROM entries WHERE id = $1', [req.params.id]);
   await logAudit(req, 'entry.permanent-delete', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2748,6 +2876,7 @@ app.post('/api/ai/requeue-failed', requireAdmin, async (req, res) => {
   );
   if (entryAutoChecker) entryAutoChecker.notify();
   await logAudit(req, 'ai.requeue-failed', { count: rowCount });
+  invalidateEntries();
   res.json({ ok: true, count: rowCount });
 });
 
@@ -2764,6 +2893,8 @@ app.post('/api/entries/:id/ai/recheck', requireAuth, async (req, res) => {
   if (!rows.length) return res.status(404).json({ error: 'Запись не найдена' });
   if (entryAutoChecker) entryAutoChecker.notify();
   await logAudit(req, 'entry.ai.recheck', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2781,6 +2912,8 @@ app.post('/api/entries/:id/ai/revert', requireAuth, async (req, res) => {
   );
   if (!rows.length) return res.status(400).json({ error: 'Оригинал текста недоступен' });
   await logAudit(req, 'entry.ai.revert', { id: req.params.id });
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true });
 });
 
@@ -2834,6 +2967,8 @@ app.delete('/api/trash', requireAuth, requireAdmin, async (req, res) => {
   );
   rows.forEach(r => safeUnlink(r.p));
   const d = await pool.query('DELETE FROM entries WHERE deleted_at IS NOT NULL');
+  invalidateEntries();
+  invalidateStats();
   res.json({ ok: true, deleted: d.rowCount });
 });