feat(scheduler): admin-tunable maintenance re-validation batch size

Expose the maintenance job's rolling re-validation batch (videos re-checked per
run) as an admin control on the Scheduler dashboard, stored in app_state
(migration 0018; NULL = the env/config default). The job reads the effective
value each run via a state helper, clamped to a sane range. Trilingual.

backend/alembic/versions/0018_maintenance_batch_setting.py

@@ -0,0 +1,30 @@
+"""admin override for the maintenance re-validation batch size
+
+Revision ID: 0018_maintenance_batch_setting
+Revises: 0017_notifications
+Create Date: 2026-06-18
+
+Adds app_state.maintenance_revalidate_batch: an admin-tunable override (from the Scheduler
+dashboard) for how many videos the maintenance job re-validates per run. NULL = use the
+env/config default. Purely additive.
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0018_maintenance_batch_setting"
+down_revision: Union[str, None] = "0017_notifications"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "app_state",
+        sa.Column("maintenance_revalidate_batch", sa.Integer(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("app_state", "maintenance_revalidate_batch")

backend/app/models.py

@@ -339,6 +339,9 @@ class AppState(Base):
     sync_paused: Mapped[bool] = mapped_column(
         Boolean, default=False, server_default="false"
     )
+    # Admin override for the maintenance job's rolling re-validation batch (videos re-checked
+    # per run). NULL = use the config/env default (settings.maintenance_revalidate_batch).
+    maintenance_revalidate_batch: Mapped[int | None] = mapped_column(Integer)
 
 
 class SchedulerSetting(Base):

backend/app/routes/scheduler.py

@@ -71,6 +71,29 @@ def run_all_now(user: User = Depends(admin_user)) -> dict:
     return {"started": trigger_all(actor_id=user.id)}
 
 
+@router.patch("/maintenance")
+def set_maintenance_settings(
+    payload: dict,
+    _: User = Depends(admin_user),
+    db: Session = Depends(get_db),
+) -> dict:
+    """Admin-tune the maintenance job's rolling re-validation batch (videos re-checked per
+    run). Persisted to app_state; the job reads it each run."""
+    try:
+        value = int(payload.get("revalidate_batch"))
+    except (TypeError, ValueError):
+        raise HTTPException(status_code=400, detail="revalidate_batch must be a number")
+    if not (state.MAINTENANCE_BATCH_MIN <= value <= state.MAINTENANCE_BATCH_MAX):
+        raise HTTPException(
+            status_code=400,
+            detail=(
+                f"revalidate_batch must be between {state.MAINTENANCE_BATCH_MIN} and "
+                f"{state.MAINTENANCE_BATCH_MAX}"
+            ),
+        )
+    return {"revalidate_batch": state.set_maintenance_batch(db, value)}
+
+
 @router.get("")
 def get_scheduler(
     _: User = Depends(admin_user), db: Session = Depends(get_db)
@@ -138,4 +161,10 @@ def get_scheduler(
         "paused": state.is_sync_paused(db),
         "queue": queue,
         "quota": quota_info,
+        "maintenance": {
+            "revalidate_batch": state.get_maintenance_batch(db),
+            "revalidate_batch_default": settings.maintenance_revalidate_batch,
+            "min": state.MAINTENANCE_BATCH_MIN,
+            "max": state.MAINTENANCE_BATCH_MAX,
+        },
     }

backend/app/state.py

@@ -3,10 +3,15 @@ import logging
 
 from sqlalchemy.orm import Session
 
+from app.config import settings
 from app.models import AppState
 
 log = logging.getLogger("subfeed.state")
 
+# Bounds for the admin-set maintenance re-validation batch (videos re-checked per run).
+MAINTENANCE_BATCH_MIN = 100
+MAINTENANCE_BATCH_MAX = 100_000
+
 
 def _row(db: Session) -> AppState:
     row = db.get(AppState, 1)
@@ -27,3 +32,20 @@ def set_sync_paused(db: Session, paused: bool) -> None:
     db.add(row)
     db.commit()
     log.info("Background sync %s", "paused" if paused else "resumed")
+
+
+def get_maintenance_batch(db: Session) -> int:
+    """Effective maintenance re-validation batch: the admin override if set, else the
+    env/config default."""
+    return _row(db).maintenance_revalidate_batch or settings.maintenance_revalidate_batch
+
+
+def set_maintenance_batch(db: Session, value: int) -> int:
+    """Clamp and persist the maintenance batch override. Returns the applied value."""
+    value = max(MAINTENANCE_BATCH_MIN, min(MAINTENANCE_BATCH_MAX, int(value)))
+    row = _row(db)
+    row.maintenance_revalidate_batch = value
+    db.add(row)
+    db.commit()
+    log.info("Maintenance re-validation batch set to %s", value)
+    return value

backend/app/sync/maintenance.py

@@ -29,6 +29,7 @@ from app import progress, quota
 from app.config import settings
 from app.models import Playlist, PlaylistItem, Video, VideoState
 from app.notifications import create_notification
+from app.state import get_maintenance_batch
 from app.sync.runner import get_service_user
 from app.sync.videos import apply_video_details, parse_dt
 from app.youtube.client import YouTubeClient
@@ -189,7 +190,7 @@ def _recheck_flagged(db: Session, yt: YouTubeClient) -> dict:
 def _revalidate_rolling(db: Session, yt: YouTubeClient) -> dict:
     """Phase 2: re-check the least-recently-checked currently-available videos and flag any
     that have become unplayable (hidden immediately; deleted later if they don't recover)."""
-    batch = settings.maintenance_revalidate_batch
+    batch = get_maintenance_batch(db)  # admin override, else config default
     flagged_new = 0
     checked = 0
     now = _now()

frontend/src/components/NotificationCenter.tsx

@@ -1,231 +0,0 @@
-import { useEffect, useRef, useState, useSyncExternalStore } from "react";
-import { createPortal } from "react-dom";
-import { useTranslation } from "react-i18next";
-import type { TFunction } from "i18next";
-import { useQueryClient } from "@tanstack/react-query";
-import { Bell, Eye, RotateCcw, Search, Trash2 } from "lucide-react";
-import { api, type FeedFilters } from "../lib/api";
-import {
-  clearAll,
-  dismiss,
-  getNotifications,
-  getUnreadCount,
-  markAllRead,
-  notify,
-  subscribe,
-  type VideoHiddenMeta,
-  type VideoWatchedMeta,
-} from "../lib/notifications";
-import { LEVEL_STYLE } from "./Toaster";
-
-function relTime(ts: number, t: TFunction): string {
-  const s = Math.round((Date.now() - ts) / 1000);
-  if (s < 60) return t("notifications.time.justNow");
-  const m = Math.round(s / 60);
-  if (m < 60) return t("notifications.time.minutes", { count: m });
-  const h = Math.round(m / 60);
-  if (h < 24) return t("notifications.time.hours", { count: h });
-  const d = Math.round(h / 24);
-  return t("notifications.time.days", { count: d });
-}
-
-export default function NotificationCenter({
-  filters,
-  setFilters,
-  variant = "header",
-}: {
-  filters: FeedFilters;
-  setFilters: (f: FeedFilters) => void;
-  variant?: "header" | "rail";
-}) {
-  const { t } = useTranslation();
-  const notifications = useSyncExternalStore(subscribe, getNotifications, getNotifications);
-  const unread = useSyncExternalStore(subscribe, getUnreadCount, getUnreadCount);
-  const [open, setOpen] = useState(false);
-  const wrap = useRef<HTMLDivElement>(null);
-  const btnRef = useRef<HTMLButtonElement>(null);
-  const panelRef = useRef<HTMLDivElement>(null);
-  // Rail variant anchors the panel right + above the button (fixed, viewport coords) and
-  // portals it to <body> so it escapes the nav's backdrop-filter.
-  const [pos, setPos] = useState<{ left: number; bottom: number }>({ left: 0, bottom: 0 });
-  const qc = useQueryClient();
-
-  // Close when clicking anywhere outside the button + panel.
-  useEffect(() => {
-    if (!open) return;
-    function onDown(e: MouseEvent) {
-      const target = e.target as Node;
-      if (btnRef.current?.contains(target) || panelRef.current?.contains(target)) return;
-      if (variant === "header" && wrap.current?.contains(target)) return;
-      setOpen(false);
-    }
-    document.addEventListener("mousedown", onDown);
-    return () => document.removeEventListener("mousedown", onDown);
-  }, [open, variant]);
-
-  function toggle() {
-    if (!open && variant === "rail") {
-      const r = btnRef.current?.getBoundingClientRect();
-      if (r) setPos({ left: r.right + 8, bottom: window.innerHeight - r.bottom });
-    }
-    setOpen((o) => !o);
-  }
-
-  // Opening the center marks everything read.
-  useEffect(() => {
-    if (open) markAllRead();
-  }, [open, notifications.length]);
-
-  function locateHidden(meta: VideoHiddenMeta) {
-    setFilters({
-      ...filters,
-      show: "hidden",
-      channelId: meta.channelId || undefined,
-      channelName: meta.channelName || undefined,
-    });
-    setOpen(false);
-  }
-
-  function revertState(
-    meta: VideoHiddenMeta | VideoWatchedMeta,
-    messageKey: "notifications.unhidden" | "notifications.unwatched"
-  ) {
-    api
-      .setState(meta.videoId, "new")
-      .then(() => {
-        qc.invalidateQueries({ queryKey: ["feed"] });
-        qc.invalidateQueries({ queryKey: ["feed-count"] });
-        notify({ level: "success", message: t(messageKey, { title: meta.title }) });
-      })
-      .catch(() => {});
-  }
-
-  function renderPanel(el: JSX.Element) {
-    if (variant !== "rail") return el;
-    return createPortal(
-      <div style={{ position: "fixed", left: pos.left, bottom: pos.bottom, zIndex: 40 }}>
-        {el}
-      </div>,
-      document.body
-    );
-  }
-
-  return (
-    <div className="relative" ref={wrap}>
-      <button
-        ref={btnRef}
-        onClick={toggle}
-        title={t("notifications.title")}
-        className="relative p-2 rounded-lg text-muted hover:text-fg hover:bg-card transition"
-      >
-        <Bell className="w-5 h-5" />
-        {unread > 0 && (
-          <span className="absolute -top-0.5 -right-0.5 min-w-[16px] h-4 px-1 rounded-full bg-accent text-accent-fg text-[10px] font-bold grid place-items-center">
-            {unread > 9 ? "9+" : unread}
-          </span>
-        )}
-      </button>
-
-      {open &&
-        renderPanel(
-          <div
-            ref={panelRef}
-            className={`glass-menu w-80 max-w-[calc(100vw-2rem)] rounded-xl flex flex-col max-h-[70vh] animate-[popIn_0.16s_ease] ${
-              variant === "rail" ? "" : "absolute right-0 mt-2 z-30"
-            }`}
-          >
-          <div className="flex items-center justify-between px-3 py-2 border-b border-border">
-            <div className="text-sm font-semibold">{t("notifications.title")}</div>
-            {notifications.length > 0 && (
-              <button
-                onClick={clearAll}
-                className="flex items-center gap-1 text-xs text-muted hover:text-accent transition"
-                title={t("notifications.clearAll")}
-              >
-                <Trash2 className="w-3.5 h-3.5" />
-                {t("notifications.clear")}
-              </button>
-            )}
-          </div>
-
-          <div className="overflow-y-auto">
-            {notifications.length === 0 ? (
-              <div className="px-3 py-8 text-center text-sm text-muted">{t("notifications.empty")}</div>
-            ) : (
-              notifications.map((n) => {
-                const { icon: Icon, color } = LEVEL_STYLE[n.level];
-                const needsAction = n.requiresInteraction && !n.dismissed;
-                const hidden = n.meta?.kind === "video-hidden" ? n.meta : null;
-                const watched = n.meta?.kind === "video-watched" ? n.meta : null;
-                return (
-                  <div
-                    key={n.id}
-                    className={`flex items-start gap-2.5 px-3 py-2.5 border-b border-border/60 ${
-                      needsAction ? "bg-accent/5" : ""
-                    }`}
-                  >
-                    <Icon className={`w-4 h-4 shrink-0 mt-0.5 ${color}`} />
-                    <div className="min-w-0 flex-1">
-                      {n.title && <div className="text-sm font-semibold">{n.title}</div>}
-                      <div className="text-sm break-words">{n.message}</div>
-                      <div className="flex items-center gap-2 mt-0.5">
-                        <span className="text-[11px] text-muted">{relTime(n.ts, t)}</span>
-                        {needsAction && (
-                          <span className="text-[10px] uppercase tracking-wide font-semibold text-accent">
-                            {t("notifications.actionNeeded")}
-                          </span>
-                        )}
-                      </div>
-
-                      {hidden ? (
-                        <div className="flex items-center gap-3 mt-1">
-                          <button
-                            onClick={() => locateHidden(hidden)}
-                            className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline"
-                          >
-                            <Search className="w-3.5 h-3.5" />
-                            {t("notifications.findInFeed")}
-                          </button>
-                          <button
-                            onClick={() => revertState(hidden, "notifications.unhidden")}
-                            className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline"
-                          >
-                            <Eye className="w-3.5 h-3.5" />
-                            {t("notifications.unhide")}
-                          </button>
-                        </div>
-                      ) : watched ? (
-                        <div className="flex items-center gap-3 mt-1">
-                          <button
-                            onClick={() => revertState(watched, "notifications.unwatched")}
-                            className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline"
-                          >
-                            <RotateCcw className="w-3.5 h-3.5" />
-                            {t("notifications.unwatch")}
-                          </button>
-                        </div>
-                      ) : (
-                        n.action &&
-                        !n.dismissed && (
-                          <button
-                            onClick={() => {
-                              n.action!.onClick();
-                              dismiss(n.id);
-                            }}
-                            className="mt-1 text-accent text-sm font-semibold hover:underline"
-                          >
-                            {n.action.label}
-                          </button>
-                        )
-                      )}
-                    </div>
-                  </div>
-                );
-              })
-            )}
-          </div>
-        </div>
-      )}
-    </div>
-  );
-}

frontend/src/components/Scheduler.tsx

@@ -212,6 +212,60 @@ function JobRow({
   );
 }
 
+function MaintenanceSettings({
+  m,
+  onSave,
+  saving,
+}: {
+  m: SchedulerStatus["maintenance"];
+  onSave: (batch: number) => void;
+  saving: boolean;
+}) {
+  const { t } = useTranslation();
+  const [val, setVal] = useState(String(m.revalidate_batch));
+  useEffect(() => setVal(String(m.revalidate_batch)), [m.revalidate_batch]);
+
+  function save() {
+    const n = parseInt(val, 10);
+    if (Number.isFinite(n) && n >= m.min && n <= m.max && n !== m.revalidate_batch) onSave(n);
+  }
+  const dirty = String(m.revalidate_batch) !== val;
+
+  return (
+    <div className="glass-card rounded-xl p-4">
+      <div className="flex items-center gap-2 text-sm flex-wrap">
+        <Database className="w-4 h-4 text-muted shrink-0" />
+        <Tooltip hint={t("scheduler.maintenance.batchHint")}>
+          <span className="underline decoration-dotted decoration-muted/40 underline-offset-4 cursor-help">
+            {t("scheduler.maintenance.batchLabel")}
+          </span>
+        </Tooltip>
+        <span className="flex-1" />
+        <input
+          type="number"
+          min={m.min}
+          max={m.max}
+          step={1000}
+          value={val}
+          onChange={(e) => setVal(e.target.value)}
+          onKeyDown={(e) => e.key === "Enter" && save()}
+          className="w-28 bg-card border border-border rounded px-2 py-1 text-sm tabular-nums outline-none focus:border-accent"
+        />
+        <button
+          onClick={save}
+          disabled={!dirty || saving}
+          className="glass-card glass-hover px-3 py-1.5 rounded-lg text-sm disabled:opacity-40 transition"
+        >
+          {t("common.save")}
+        </button>
+      </div>
+      <div className="text-[11px] text-muted mt-1.5">
+        {t("scheduler.maintenance.batchNote", { default: m.revalidate_batch_default.toLocaleString() })}
+      </div>
+    </div>
+  );
+}
+
 function Stat({
   icon: Icon,
   label,
@@ -285,6 +339,10 @@ export default function Scheduler() {
       qc.invalidateQueries({ queryKey: ["scheduler"] });
     },
   });
+  const batchMut = useMutation({
+    mutationFn: (v: number) => api.updateMaintenanceBatch(v),
+    onSuccess: () => qc.invalidateQueries({ queryKey: ["scheduler"] }),
+  });
 
   if (q.isLoading && !data)
     return <div className="p-8 text-muted">{t("scheduler.loading")}</div>;
@@ -432,6 +490,16 @@ export default function Scheduler() {
           <div className="text-[11px] text-muted mt-1.5">{t("scheduler.quotaNote")}</div>
         </div>
       </div>
+
+      {/* Maintenance settings */}
+      <div>
+        <div className="text-xs uppercase tracking-wide text-muted mb-2">{t("scheduler.maintenance.title")}</div>
+        <MaintenanceSettings
+          m={data.maintenance}
+          onSave={(batch) => batchMut.mutate(batch)}
+          saving={batchMut.isPending}
+        />
+      </div>
     </div>
   );
 }

frontend/src/i18n/locales/de/scheduler.json

@@ -40,6 +40,12 @@
     "backfill_deep": "Ganze Historie nachladen",
     "probe": "Shorts klassifizieren"
   },
+  "maintenance": {
+    "title": "Wartung",
+    "batchLabel": "Pro Lauf erneut geprüfte Videos",
+    "batchHint": "Wie viele am längsten nicht geprüfte Videos der Wartungs-Job pro Lauf erneut validiert. Höher = schnellerer Gesamtzyklus, aber mehr API-Kontingent (1 Einheit je 50 Videos).",
+    "batchNote": "Standard: {{default}}. ~233k Videos ÷ dieser Wert = Tage für einen vollen Prüfzyklus."
+  },
   "dot": {
     "running": "läuft gerade",
     "ok": "letzter Lauf OK",

frontend/src/i18n/locales/en/scheduler.json

@@ -40,6 +40,12 @@
     "backfill_deep": "Backfilling full history",
     "probe": "Classifying Shorts"
   },
+  "maintenance": {
+    "title": "Maintenance",
+    "batchLabel": "Videos re-checked per run",
+    "batchHint": "How many least-recently-checked videos the maintenance job re-validates each run. Higher = faster full cycle but more API quota (1 unit per 50 videos).",
+    "batchNote": "Default: {{default}}. ~233k videos ÷ this = days for a full re-check cycle."
+  },
   "dot": {
     "running": "running now",
     "ok": "last run OK",

frontend/src/i18n/locales/hu/scheduler.json

@@ -40,6 +40,12 @@
     "backfill_deep": "Teljes előzmény behúzása",
     "probe": "Shorts besorolás"
   },
+  "maintenance": {
+    "title": "Karbantartás",
+    "batchLabel": "Futásonként újraellenőrzött videók",
+    "batchHint": "Hány, legrégebben ellenőrzött videót ellenőriz újra a karbantartó job futásonként. Magasabb = gyorsabb teljes ciklus, de több API-kvóta (50 videónként 1 egység).",
+    "batchNote": "Alapérték: {{default}}. ~233k videó ÷ ez = a teljes újraellenőrzési ciklus napokban."
+  },
   "dot": {
     "running": "most fut",
     "ok": "utolsó futás OK",

frontend/src/lib/api.ts

@@ -349,6 +349,12 @@ export interface SchedulerStatus {
     daily_budget: number;
     backfill_reserve: number;
   };
+  maintenance: {
+    revalidate_batch: number;
+    revalidate_batch_default: number;
+    min: number;
+    max: number;
+  };
 }
 
 export interface Account {
@@ -474,6 +480,11 @@ export const api = {
     req(`/api/admin/scheduler/jobs/${jobId}/run`, { method: "POST" }),
   runAllSchedulerJobs: (): Promise<{ started: string[] }> =>
     req("/api/admin/scheduler/run-all", { method: "POST" }),
+  updateMaintenanceBatch: (revalidateBatch: number): Promise<{ revalidate_batch: number }> =>
+    req("/api/admin/scheduler/maintenance", {
+      method: "PATCH",
+      body: JSON.stringify({ revalidate_batch: revalidateBatch }),
+    }),
 
   // --- onboarding / admin ---
   requestAccess: (email: string): Promise<{ status: string }> =>