Keep logs for a set number of days

Logs grew forever. A daily prune-logs cron now deletes entries older
than the app setting logs_keep_days (Settings > General, super admin;
default AppData.LogsKeepDays, 90), with an index on logs.created_at.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/pages/admin/settings/general/index.tsx

@@ -3,6 +3,7 @@ import ChatroomRetentionSection from "./(sections)/chatroom-retention-section";
 import HookCallRetentionSection from "./(sections)/hook-call-retention-section";
 import InstallIconSection from "./(sections)/install-icon-section";
 import InstallNameSection from "./(sections)/install-name-section";
+import LogRetentionSection from "./(sections)/log-retention-section";
 import NotificationsSection from "./(sections)/notifications-section";
 import PromptSection from "./(sections)/prompt-section";
 import RunLimitsSection from "./(sections)/run-limits-section";
@@ -29,6 +30,7 @@ export default function AdminSettingsGeneralPage() {
             <SkillLimitsSection />
             <HookCallRetentionSection />
             <ChatroomRetentionSection />
+            <LogRetentionSection />
             <StorageSection />
             <VersionSection />
         </SettingsShell>