feat(i18n): every server A→Z list in the reader's alphabet (E30 S3)

The Postgres image is Alpine, whose en_US.utf8 is byte order: "Életrajzi" and
"Ötödik" sorted after "Zorró" in the feed, the channel lists, the Plex grid,
its genres and collections. `app/collation.py` names the ICU collation of the
reader's language (hu-x-icu puts "Ö" after "O" and "Cs" after "Cu"), wraps
every text ORDER BY with it - the feed's keyset cursor compares with the same
expression, so paging walks the order it sorted in - and orders the lists built
in Python (genre and studio facets, collection members, the discovery re-sort)
through the same collation. Plex title tiebreaks use the shown (HU) title.

backend/app/routes/plex/detail.py

@@ -7,9 +7,10 @@ from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime, timezone
 
 from fastapi import APIRouter, Depends
-from sqlalchemy import func, select
+from sqlalchemy import select
 from sqlalchemy.orm import Session
 
+from app.collation import collated, sorted_words
 from app import logs
 from app.auth import current_user
 from app.db import get_db
@@ -25,6 +26,7 @@ from app.models import (
 from app.plex import detail as plex_detail
 from app.plex import people as plex_people
 from app.plex import rollup, subtitles
+from app.plex.query import title_col
 from app.plex import tmdb as plex_tmdb
 from app.plex.cards import episode_card, movie_card, show_card
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
@@ -277,7 +279,8 @@ def _collection_strips(db: Session, it: PlexItem, user_id: int, lang: str) -> li
         ).scalars()
     }
     # Smallest (most specific — e.g. a franchise) first; the big auto-lists (IMDb/TMDb Popular) last.
-    ordered = sorted((c for c in cols.values()), key=lambda c: (c.child_count or 0, c.title))
+    alpha = {w: i for i, w in enumerate(sorted_words(db, [c.title for c in cols.values()], lang))}
+    ordered = sorted(cols.values(), key=lambda c: (c.child_count or 0, alpha[c.title]))
     out = []
     for col in ordered:
         rk = col.rating_key
@@ -289,7 +292,9 @@ def _collection_strips(db: Session, it: PlexItem, user_id: int, lang: str) -> li
                     PlexItem.kind == "movie",
                     PlexItem.collection_keys.contains([rk]),
                 )
-                .order_by(PlexItem.year.asc().nullslast(), func.lower(PlexItem.title))
+                .order_by(
+                    PlexItem.year.asc().nullslast(), collated(title_col(PlexItem, lang), lang)
+                )
                 .limit(60)
             )
             .scalars()