feat(scheduler): admin run-now/run-all triggers + live progress + completion notices

Add per-job "Run now" buttons and a "Start all now" button to the admin Scheduler
dashboard (admin-gated endpoints). Triggers run the job in a background thread
independent of its interval, refusing a concurrent run (409). While running, the
long jobs (maintenance, enrich, backfill, shorts) report live progress through a
decoupled contextvar sink, shown as a progress bar on the job row via the existing
4s poll. A manually-triggered run posts a completion notification to the triggering
admin's inbox (scheduled runs stay silent to avoid spam); the inbox renders the
"scheduler" type trilingually from type+data. While here, give the maintenance job
its missing dashboard label/description in all three languages.

backend/app/sync/maintenance.py

@@ -25,7 +25,7 @@ from datetime import datetime, timedelta, timezone
 from sqlalchemy import or_, select
 from sqlalchemy.orm import Session
 
-from app import quota
+from app import progress, quota
 from app.config import settings
 from app.models import Playlist, PlaylistItem, Video, VideoState
 from app.notifications import create_notification
@@ -147,6 +147,7 @@ def _recheck_flagged(db: Session, yt: YouTubeClient) -> dict:
     )
     if not flagged:
         return {"checked": 0, "recovered": 0, "deleted": 0, "notified": 0}
+    progress.report(0, len(flagged), "recheck")
     items = {it["id"]: it for it in yt.get_videos([v.id for v in flagged])}
     now = _now()
     recovered = 0
@@ -221,6 +222,7 @@ def _revalidate_rolling(db: Session, yt: YouTubeClient) -> dict:
                 flagged_new += 1
         db.commit()
         checked += len(page)
+        progress.report(checked, batch, "revalidate")
     return {"checked": checked, "flagged": flagged_new}
 
 

backend/app/sync/runner.py

@@ -9,7 +9,7 @@ import logging
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
-from app import quota
+from app import progress, quota
 from app.config import settings
 
 log = logging.getLogger("subfeed.sync")
@@ -64,6 +64,7 @@ def run_enrich(db: Session, max_batches: int = 200, floor: int = 200) -> int:
                 break
             n = enrich_pending(db, yt)
             total += n
+            progress.report(total, None, "enrich")  # total unknown (drains until empty)
             if n == 0:
                 break
         # Revisit transient live/upcoming videos (enrich_pending is one-shot) so an ended
@@ -121,6 +122,7 @@ def run_recent_backfill(
             try:
                 videos_added += backfill_channel_recent(db, yt, channel)
                 processed += 1
+                progress.report(processed, len(channels), "backfill_recent")
             except Exception:
                 db.rollback()
                 log.exception("Recent backfill failed for channel %s", channel.id)
@@ -166,6 +168,7 @@ def run_deep_backfill(db: Session, max_channels: int = 10, max_pages: int = 5) -
             try:
                 videos_added += backfill_channel_deep(db, yt, channel, max_pages)
                 processed += 1
+                progress.report(processed, len(channels), "backfill_deep")
             except Exception:
                 db.rollback()
                 log.exception("Deep backfill failed for channel %s", channel.id)

backend/app/sync/videos.py

@@ -9,6 +9,7 @@ from sqlalchemy import and_, func, or_, select, update
 from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.orm import Session
 
+from app import progress
 from app.config import settings
 from app.models import Channel, Video
 from app.youtube.client import YouTubeClient, best_thumbnail
@@ -365,5 +366,6 @@ def run_shorts_classification(db: Session, limit: int | None = None) -> dict:
                 probed += 1
                 if result:
                     shorts += 1
+                progress.report(probed, len(candidates), "probe")
     db.commit()
     return {"probed": probed, "shorts": shorts}