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/api/admin/settings/log-retention.ts

@@ -0,0 +1,45 @@
+import grabSuperAdminUser from "@/src/functions/backend/backups/grab-super-admin-user";
+import grabLogRetentionOverview from "@/src/functions/backend/db/app-settings/grab-logs-keep-days";
+import saveAppSetting from "@/src/functions/backend/db/app-settings/save-app-setting";
+import logEvent, { grabRequestIP } from "@/src/functions/backend/logger";
+import { LogsKeepDaysSettingKey } from "@/src/dict/log-categories";
+import { SaveLogRetentionRequestSchema } from "@/src/schemas/log-schema";
+import type { LogRetentionOverview } from "@/src/types";
+import AppError from "@/src/utils/app-error";
+import parseWithSchema from "@/src/utils/parse-with-schema";
+import safeErrorMessage from "@/src/utils/safe-error-message";
+import type { APIResponseObject, BunextAPIRouteHandler } from "@moduletrace/bunext/types";
+
+/**
+ * Super admin only: how many days logs are kept before the daily prune
+ * deletes them. Zero puts the code's default back.
+ */
+export const handler: BunextAPIRouteHandler<APIResponseObject<LogRetentionOverview>> = async ({ req, body }) => {
+    try {
+        if (req.method != "POST") throw new AppError(`Method not allowed`);
+
+        const user = await grabSuperAdminUser({ req });
+
+        if (!user?.id) throw new AppError(`Only a super admin can change how long logs are kept.`);
+
+        const { keep_days } = parseWithSchema({ schema: SaveLogRetentionRequestSchema, data: body });
+
+        await saveAppSetting({
+            key: LogsKeepDaysSettingKey,
+            value: keep_days > 0 ? String(keep_days) : null,
+        });
+
+        await logEvent({
+            title: "Log retention changed",
+            category: "system",
+            user_id: user.id,
+            plain_text: `User #${user.id} set logs to be kept for ${keep_days || "the default number of"} days.`,
+            metadata: { keep_days },
+            ip_address: grabRequestIP(req),
+        });
+
+        return { success: true, singleRes: await grabLogRetentionOverview() };
+    } catch (error: unknown) {
+        return { success: false, msg: safeErrorMessage({ error }) };
+    }
+};