feat: unhide action, date-range filter, more sort options

- Hidden view shows an Unhide action (eye icon) instead of Hide
- Upload-date filter: From/To date range (inclusive); feed shows only videos
  published in that window (backend published_after / published_before)
- New sort options: Name (A-Z) and Channel subscribers, alongside date/views/
  duration/shuffle
- Native controls follow the theme via color-scheme (dark date picker)

backend/app/routes/feed.py

@@ -1,4 +1,4 @@
-from datetime import datetime, timezone
+from datetime import date, datetime, timedelta, timezone
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from sqlalchemy import and_, false, func, or_, select
@@ -50,6 +50,8 @@ def get_feed(
     min_duration: int | None = None,
     max_duration: int | None = None,
     max_age_days: int | None = None,
+    published_after: date | None = None,
+    published_before: date | None = None,
     show_normal: bool = True,
     include_shorts: bool = False,
     include_live: bool = False,
@@ -119,6 +121,17 @@ def get_feed(
         query = query.where(
             Video.published_at >= datetime.fromtimestamp(cutoff, tz=timezone.utc)
         )
+    if published_after is not None:
+        start = datetime.combine(
+            published_after, datetime.min.time(), tzinfo=timezone.utc
+        )
+        query = query.where(Video.published_at >= start)
+    if published_before is not None:
+        # Inclusive of the end day.
+        end = datetime.combine(
+            published_before, datetime.min.time(), tzinfo=timezone.utc
+        ) + timedelta(days=1)
+        query = query.where(Video.published_at < end)
     if q:
         # Title (and channel name) only — searching descriptions produced noisy matches.
         like = f"%{q}%"
@@ -168,6 +181,8 @@ def get_feed(
         "views": Video.view_count.desc().nulls_last(),
         "duration_desc": Video.duration_seconds.desc().nulls_last(),
         "duration_asc": Video.duration_seconds.asc().nulls_last(),
+        "title": func.lower(Video.title).asc().nulls_last(),
+        "subscribers": Channel.subscriber_count.desc().nulls_last(),
         "shuffle": func.md5(func.concat(Video.id, str(seed))),
     }
     query = query.order_by(sorts.get(sort, sorts["newest"]))