reworked settings page

backend/server.js

@@ -794,6 +794,15 @@ db.exec(`
   );
 `);
 
+db.exec(`
+  CREATE TABLE IF NOT EXISTS maintenance_settings (
+    id INTEGER PRIMARY KEY CHECK (id = 1),
+    search_retention_days INTEGER DEFAULT ${SEARCH_POST_RETENTION_DAYS},
+    auto_purge_hidden INTEGER DEFAULT 1,
+    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+  );
+`);
+
 db.exec(`
   CREATE INDEX IF NOT EXISTS idx_search_seen_posts_last_seen_at
   ON search_seen_posts(last_seen_at);
@@ -1546,9 +1555,62 @@ function getFormattedCredentialById(id) {
   return formatCredentialRow(row[0]);
 }
 
+function normalizeRetentionDays(value) {
+  const parsed = parseInt(value, 10);
+  if (Number.isNaN(parsed) || parsed <= 0) {
+    return SEARCH_POST_RETENTION_DAYS;
+  }
+  return Math.min(365, Math.max(1, parsed));
+}
+
+function loadHiddenSettings() {
+  let settings = db.prepare('SELECT * FROM maintenance_settings WHERE id = 1').get();
+  if (!settings) {
+    const defaults = {
+      id: 1,
+      search_retention_days: SEARCH_POST_RETENTION_DAYS,
+      auto_purge_hidden: 1
+    };
+    db.prepare(`
+      INSERT INTO maintenance_settings (id, search_retention_days, auto_purge_hidden, updated_at)
+      VALUES (1, ?, ?, CURRENT_TIMESTAMP)
+    `).run(defaults.search_retention_days, defaults.auto_purge_hidden);
+    settings = defaults;
+  }
+  settings.search_retention_days = normalizeRetentionDays(settings.search_retention_days);
+  settings.auto_purge_hidden = settings.auto_purge_hidden ? 1 : 0;
+  return settings;
+}
+
+function persistHiddenSettings({ retentionDays, autoPurgeEnabled }) {
+  const normalizedRetention = normalizeRetentionDays(retentionDays);
+  const normalizedAuto = autoPurgeEnabled ? 1 : 0;
+  const existing = db.prepare('SELECT id FROM maintenance_settings WHERE id = 1').get();
+  if (existing) {
+    db.prepare(`
+      UPDATE maintenance_settings
+      SET search_retention_days = ?, auto_purge_hidden = ?, updated_at = CURRENT_TIMESTAMP
+      WHERE id = 1
+    `).run(normalizedRetention, normalizedAuto);
+  } else {
+    db.prepare(`
+      INSERT INTO maintenance_settings (id, search_retention_days, auto_purge_hidden, updated_at)
+      VALUES (1, ?, ?, CURRENT_TIMESTAMP)
+    `).run(normalizedRetention, normalizedAuto);
+  }
+  return {
+    auto_purge_enabled: !!normalizedAuto,
+    retention_days: normalizedRetention
+  };
+}
+
 function cleanupExpiredSearchPosts() {
   try {
-    const threshold = `-${SEARCH_POST_RETENTION_DAYS} day`;
+    const settings = loadHiddenSettings();
+    if (!settings.auto_purge_hidden) {
+      return;
+    }
+    const threshold = `-${settings.search_retention_days} day`;
     db.prepare(`
       DELETE FROM search_seen_posts
       WHERE last_seen_at < DATETIME('now', ?)
@@ -3197,6 +3259,33 @@ app.put('/api/ai-settings', (req, res) => {
   }
 });
 
+app.get('/api/hidden-settings', (req, res) => {
+  try {
+    const settings = loadHiddenSettings();
+    res.json({
+      auto_purge_enabled: !!settings.auto_purge_hidden,
+      retention_days: settings.search_retention_days
+    });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
+app.put('/api/hidden-settings', (req, res) => {
+  try {
+    const body = req.body || {};
+    const retentionDays = normalizeRetentionDays(body.retention_days);
+    const autoPurgeEnabled = !!body.auto_purge_enabled;
+    const saved = persistHiddenSettings({ retentionDays, autoPurgeEnabled });
+    if (saved.auto_purge_enabled) {
+      cleanupExpiredSearchPosts();
+    }
+    res.json(saved);
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
 function sanitizeAIComment(text) {
   if (!text) {
     return '';