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/README.md

@@ -23,7 +23,8 @@ Three layers, by *who* runs the code — not by feature:
 3. **Flat `app/*.py` core modules — cross-cutting primitives.** `auth`, `sysconfig`, `quota`, `audit`,
    `notifications`, `userscope`, `realtime`, `ratelimit`, `progress`, `logs` (the one logging
    configuration), `logsink` (its `log_events` table), `diagnostics` (a user's consented log
-   level) and `debugsession` (a recording that tags its user's lines, E16), … are single-file primitives many layers import. They depend on nothing above them (a core
+   level), `debugsession` (a recording that tags its user's lines, E16) and `collation` (A→Z in the
+   reader's alphabet, E30), … are single-file primitives many layers import. They depend on nothing above them (a core
    module must never import a `routes/…` module).
 
 **Extraction trigger: the SECOND consumer.** Keep new logic inline in its first caller. The moment a

backend/app/collation.py

@@ -0,0 +1,39 @@
+"""Alphabetical order in the reader's language (E30 S3).
+
+Why not the database default: the Postgres image is Alpine, and musl's `en_US.utf8` collation is BYTE
+order — every accented initial sorted after "Z" ("Zorró < Életrajzi < Ötödik"), in every A→Z list the
+server orders. Postgres ships the ICU collations on the same image (dev, test, prod alike), so a text
+sort names one: Hungarian puts "Ö" after "O" and "Cs" after "Cu", English folds the accents in.
+
+`collated` wraps an ORDER BY expression — and because a keyset cursor compares with the SAME expression
+(`feedquery.sort_keys`), the cursor pages in the same order it sorted in. `sorted_words` orders a Python
+list the same way through the database, so a list built in Python matches one built in SQL exactly."""
+
+from typing import Any
+
+from sqlalchemy import SQLColumnExpression, column, func, select, values
+from sqlalchemy.orm import Session
+from sqlalchemy.sql.elements import ColumnElement
+from sqlalchemy.types import String
+
+from app.mailtext import normalize
+
+ICU: dict[str, str] = {"en": "en-x-icu", "hu": "hu-x-icu"}
+
+
+def collation(lang: str | None) -> str:
+    """The ICU collation for a UI language; anything unknown sorts as English."""
+    return ICU[normalize(lang)]
+
+
+def collated(expr: SQLColumnExpression[Any], lang: str | None) -> ColumnElement[Any]:
+    """`expr` compared in the reader's alphabet. Case-folded, so "apple" and "Apple" sit together."""
+    return func.lower(expr).collate(collation(lang))
+
+
+def sorted_words(db: Session, words: list[str], lang: str | None) -> list[str]:
+    """`words` in the reader's alphabetical order, by the same ICU collation as `collated`."""
+    if not words:
+        return []
+    w = values(column("w", String), name="words").data([(x,) for x in words])
+    return list(db.scalars(select(w.c.w).order_by(collated(w.c.w, lang), w.c.w)))

backend/app/feedquery.py

@@ -15,6 +15,7 @@ from datetime import date, datetime, timedelta, timezone
 from sqlalchemy import BigInteger, Select, and_, cast, false, func, or_, select
 from sqlalchemy.orm import Session, aliased
 
+from app.collation import collated
 from app.models import (
     LIVE_OR_UPCOMING,
     BlockedChannel,
@@ -478,8 +479,10 @@ def feed_years(db: Session, user: User, **params) -> list[dict]:
 # replaces OFFSET/LIMIT: deep scrolling no longer scans-and-discards skipped rows,
 # and the page boundary is stable even as the scheduler ingests new videos mid-scroll
 # (OFFSET would shift and duplicate/skip rows).
-def sort_keys(sort: str, seed: int, rank_expr=None) -> list[dict]:
+def sort_keys(sort: str, seed: int, rank_expr=None, lang: str | None = None) -> list[dict]:
+    """`lang` orders the title sorts in the reader's alphabet (`collation`); the other keys ignore it."""
     pub = {"expr": Video.published_at, "asc": False, "nullable": False, "kind": "dt"}
+    title = collated(Video.title, lang)
     table: dict[str, list[dict]] = {
         "newest": [pub],
         "oldest": [{**pub, "asc": True}],
@@ -491,10 +494,8 @@ def sort_keys(sort: str, seed: int, rank_expr=None) -> list[dict]:
         "duration_asc": [
             {"expr": Video.duration_seconds, "asc": True, "nullable": True, "kind": "num"}
         ],
-        "title": [{"expr": func.lower(Video.title), "asc": True, "nullable": True, "kind": "str"}],
-        "title_desc": [
-            {"expr": func.lower(Video.title), "asc": False, "nullable": True, "kind": "str"}
-        ],
+        "title": [{"expr": title, "asc": True, "nullable": True, "kind": "str"}],
+        "title_desc": [{"expr": title, "asc": False, "nullable": True, "kind": "str"}],
         "subscribers": [
             {"expr": Channel.subscriber_count, "asc": False, "nullable": True, "kind": "num"}
         ],

backend/app/routes/channels.py

@@ -9,6 +9,8 @@ from pydantic import BaseModel
 from sqlalchemy import func, select, update
 from sqlalchemy.orm import Session
 
+from app.collation import collated, sorted_words
+from app.mailtext import lang_for_user
 from app import logs, quota
 from app.auth import admin_user, current_user, require_human, require_write_scope
 from app.db import get_db
@@ -44,7 +46,7 @@ def list_channels(user: User = Depends(current_user), db: Session = Depends(get_
         select(Subscription, Channel)
         .join(Channel, Channel.id == Subscription.channel_id)
         .where(Subscription.user_id == user.id)
-        .order_by(Subscription.priority.desc(), func.lower(Channel.title))
+        .order_by(Subscription.priority.desc(), collated(Channel.title, lang_for_user(user)))
     ).all()
 
     # Per-channel aggregates over the shared catalog in ONE grouped pass: stored count, last
@@ -139,7 +141,7 @@ def _discovery_rows(db: Session, user: User) -> list:
     return db.execute(
         q.group_by(Channel.id).order_by(
             func.count(func.distinct(PlaylistItem.video_id)).desc(),
-            func.lower(Channel.title),
+            collated(Channel.title, lang_for_user(user)),
         )
     ).all()
 
@@ -192,10 +194,14 @@ def discover_channels(
             ):
                 apply_channel_details(db, yt.get_channels(need), need)
             db.commit()
-            # Match _discovery_rows' ORDER BY exactly: video-count DESC, then title (NULLs LAST,
-            # as Postgres orders them — coercing NULL→"" would wrongly float untitled channels up).
+            # Match _discovery_rows' ORDER BY exactly: video-count DESC, then title in the reader's
+            # alphabet (NULLs LAST, as Postgres orders them — coercing NULL→"" would wrongly float
+            # untitled channels up).
+            titles = [r[0].title for r in rows if r[0].title is not None]
+            alpha = {w: i for i, w in enumerate(sorted_words(db, titles, lang_for_user(user)))}
             rows = sorted(
-                rows, key=lambda r: (-int(r[1]), r[0].title is None, (r[0].title or "").lower())
+                rows,
+                key=lambda r: (-int(r[1]), r[0].title is None, alpha.get(r[0].title or "", 0)),
             )
         except YouTubeError as exc:
             log.warning(
@@ -659,7 +665,7 @@ def list_blocked(user: User = Depends(current_user), db: Session = Depends(get_d
             select(Channel)
             .join(BlockedChannel, BlockedChannel.channel_id == Channel.id)
             .where(BlockedChannel.user_id == user.id)
-            .order_by(func.lower(Channel.title))
+            .order_by(collated(Channel.title, lang_for_user(user)))
         )
         .scalars()
         .all()

backend/app/routes/downloads.py

@@ -21,6 +21,8 @@ from pydantic import BaseModel
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
+from app.mailtext import lang_for_user
+from app.collation import collated
 from app import audit, sysconfig
 from app.auth import admin_user, require_human
 from app.config import settings
@@ -988,7 +990,7 @@ def share_recipients(
         db.execute(
             select(User)
             .where(User.id != user.id, *messageable_clauses())
-            .order_by(func.lower(User.email))
+            .order_by(collated(User.email, lang_for_user(user)))
         )
         .scalars()
         .all()

backend/app/routes/feed.py

@@ -10,6 +10,7 @@ from sqlalchemy.orm.exc import StaleDataError
 from app import quota
 from app.auth import current_user
 from app.db import get_db
+from app.mailtext import lang_for_user
 from app.feedquery import (
     decode_cursor,
     encode_cursor,
@@ -108,7 +109,7 @@ def get_feed(
     db: Session = Depends(get_db),
 ) -> dict:
     query, rank_expr = filtered_query(db, user, **params)
-    keys = sort_keys(sort, seed, rank_expr)
+    keys = sort_keys(sort, seed, rank_expr, lang_for_user(user))
 
     # Expose each key column on the row so we can build the next cursor from the last item.
     query = query.add_columns(*[k["expr"].label(f"_k{i}") for i, k in enumerate(keys)])

backend/app/routes/messages.py

@@ -21,6 +21,8 @@ from pydantic import BaseModel
 from sqlalchemy import and_, case, delete, func, or_, select
 from sqlalchemy.orm import Session
 
+from app.mailtext import lang_for_user
+from app.collation import collated
 from app.auth import require_human, resolved_user_id
 from app.db import SessionLocal, get_db
 from app.models import Message, MessageKey, User
@@ -246,7 +248,7 @@ def list_recipients(
             select(User)
             .join(MessageKey, MessageKey.user_id == User.id)
             .where(User.id != user.id, *messageable_clauses())
-            .order_by(func.lower(func.coalesce(User.display_name, User.email)))
+            .order_by(collated(func.coalesce(User.display_name, User.email), lang_for_user(user)))
         )
         .scalars()
         .all()

backend/app/routes/plex/browse.py

@@ -15,6 +15,8 @@ from sqlalchemy import (
 )
 from sqlalchemy.orm import Session, aliased
 
+from app.mailtext import lang_for_user
+from app.collation import collated, sorted_words
 from app import sysconfig
 from app.auth import current_user
 from app.db import get_db
@@ -55,14 +57,15 @@ from app.utils import to_tsquery_str
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 
 
-def sort_column(u, sort: str):
+def sort_column(u, sort: str, lang: str = "en"):
     """The browse grid's sort key -> orderable column on the union subquery. Module-level (not inline
     in the handler) so a test can pin its vocabulary to `PLEX_SORT_KEYS` — a key the Sort control
     offers but this cannot order would quietly fall back to `added_at` and look like a broken control.
-    An unknown key (a stale bookmark, a hand-edited URL) deliberately keeps that fallback."""
+    An unknown key (a stale bookmark, a hand-edited URL) deliberately keeps that fallback. The title sorts
+    in the reader's alphabet (`collation`)."""
     return {
         "added": u.c.added_at,
-        "title": func.lower(u.c.title),
+        "title": collated(u.c.title, lang),
         "year": u.c.year,
         "rating": u.c.rating,
         "duration": u.c.duration_s,
@@ -79,7 +82,7 @@ def list_libraries(user: User = Depends(current_user), db: Session = Depends(get
         db.execute(
             select(PlexLibrary)
             .where(PlexLibrary.overlay_of.is_(None))
-            .order_by(PlexLibrary.kind.desc(), PlexLibrary.title)
+            .order_by(PlexLibrary.kind.desc(), collated(PlexLibrary.title, lang_for_user(user)))
         )
         .scalars()
         .all()
@@ -238,7 +241,7 @@ def unified_library(
         if tsq is not None:
             order = [u.c.rank.desc()]
         else:
-            col = sort_column(u, sort)
+            col = sort_column(u, sort, lang)
             order = [(col.asc() if sort_dir == "asc" else col.desc()).nullslast()]
         order.append(u.c.rk.desc())
         rows = db.execute(select(u).order_by(*order).offset(offset).limit(limit)).all()
@@ -530,16 +533,19 @@ def facets(
     for c in split_csv(f.playable):
         if c in PLAYBACK_CLASSES:
             playable_counts.setdefault(c, 0)
+    # Names in the reader's alphabet: the genres are Hungarian words for a Hungarian reader (E30 S1).
+    alpha = {w: i for i, w in enumerate(sorted_words(db, [*genre_counts, *studio_counts], lang))}
     return {
         "genres": [
-            {"value": g, "count": c} for g, c in sorted(genre_counts.items(), key=lambda kv: kv[0])
+            {"value": g, "count": c}
+            for g, c in sorted(genre_counts.items(), key=lambda kv: alpha[kv[0]])
         ],
         "content_ratings": [
             {"value": cr, "count": c} for cr, c in sorted(cr_counts.items(), key=lambda kv: -kv[1])
         ],
         "studios": [
             {"value": s, "count": c}
-            for s, c in sorted(studio_counts.items(), key=lambda kv: (-kv[1], kv[0]))
+            for s, c in sorted(studio_counts.items(), key=lambda kv: (-kv[1], alpha[kv[0]]))
         ],
         # Fixed good→heavy order (not by count), so the class list reads as a severity scale.
         "playable": [

backend/app/routes/plex/collections.py

@@ -9,6 +9,8 @@ from pydantic import BaseModel
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
+from app.mailtext import lang_for_user
+from app.collation import collated, sorted_words
 from app import logs
 from app.auth import admin_user, current_user
 from app.db import get_db
@@ -25,7 +27,7 @@ from app.plex import sync as plex_sync
 from app.plex.cards import display_title, movie_card, norm_lang, show_card
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.plex.lookups import by_rating_key
-from app.plex.query import content_libs, runtime_by_key, top_art_keys
+from app.plex.query import content_libs, runtime_by_key, title_col, top_art_keys
 from app.utils import like_escape
 from app.refusal import refused
 from app.routes._common import not_found
@@ -142,7 +144,7 @@ def collections(
         db.execute(
             query.order_by(
                 PlexCollection.child_count.desc().nullslast(),
-                func.lower(PlexCollection.title),
+                collated(PlexCollection.title, lang_for_user(user)),
             )
         )
         .scalars()
@@ -208,16 +210,24 @@ MEMBER_SORT_KEYS: dict[str, Callable[[Member], Any]] = {
 DEFAULT_MEMBER_SORT = "year"
 
 
-def sort_members(members: list[Member], sort: str, sort_dir: str) -> list[Member]:
+def sort_members(
+    members: list[Member], sort: str, sort_dir: str, alpha: dict[str, int] | None = None
+) -> list[Member]:
     """Order a collection's members by one of `PLEX_SORT_KEYS`.
 
     Two properties worth stating because they are easy to get wrong with a plain `reverse=True`:
     members with no value for the key sink to the END in BOTH directions (matching the browse grid's
     `nullslast()` — a movie with no rating is not "the worst rated"), and ties always resolve
     title-ascending, so flipping the direction reverses the ranking rather than the alphabet inside
-    it. An unknown key falls back to the page's default instead of returning an arbitrary order."""
+    it. An unknown key falls back to the page's default instead of returning an arbitrary order.
+
+    `alpha` ranks each title in the reader's alphabet (`collation.sorted_words`); without it, titles
+    compare as Python strings, which puts every accented initial after "z"."""
+    by_title = (lambda m: alpha[m.title]) if alpha is not None else (lambda m: m.title)
     key = MEMBER_SORT_KEYS.get(sort, MEMBER_SORT_KEYS[DEFAULT_MEMBER_SORT])
-    ordered = sorted(members, key=lambda m: m.title)  # stable secondary, applied first
+    if key is MEMBER_SORT_KEYS["title"]:
+        key = by_title
+    ordered = sorted(members, key=by_title)  # stable secondary, applied first
     have = [m for m in ordered if key(m) is not None]
     missing = [m for m in ordered if key(m) is None]
     have.sort(key=key, reverse=sort_dir != "asc")
@@ -246,7 +256,7 @@ def collection_detail(
         db.execute(
             select(PlexItem)
             .where(PlexItem.kind == "movie", PlexItem.collection_keys.contains([rating_key]))
-            .order_by(PlexItem.year.asc().nullslast(), func.lower(PlexItem.title))
+            .order_by(PlexItem.year.asc().nullslast(), collated(title_col(PlexItem, lang), lang))
         )
         .scalars()
         .all()
@@ -255,7 +265,7 @@ def collection_detail(
         db.execute(
             select(PlexShow)
             .where(PlexShow.collection_keys.contains([rating_key]))
-            .order_by(PlexShow.year.asc().nullslast(), func.lower(PlexShow.title))
+            .order_by(PlexShow.year.asc().nullslast(), collated(title_col(PlexShow, lang), lang))
         )
         .scalars()
         .all()
@@ -310,7 +320,8 @@ def collection_detail(
         )
         for sh in shows
     ]
-    members = sort_members(members, sort, sort_dir)
+    alpha = {w: i for i, w in enumerate(sorted_words(db, [m.title for m in members], lang))}
+    members = sort_members(members, sort, sort_dir, alpha)
     items = [
         movie_card(m.obj, mstate.get(m.obj.id), lang=lang)
         if m.kind == "movie"

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()

backend/app/routes/plex/discover.py

@@ -18,6 +18,7 @@ from fastapi import APIRouter, Depends, Query
 from sqlalchemy import and_, func, or_, select
 from sqlalchemy.orm import Session
 
+from app.collation import sorted_words
 from app.auth import current_user
 from app.db import get_db
 from app.models import PlexItem, PlexShow, PlexState, User
@@ -264,7 +265,8 @@ def _genre_tiles(
         expanded = base.subquery()
         for g, c in db.execute(select(expanded.c.g, func.count()).group_by(expanded.c.g)).all():
             counts[g] = counts.get(g, 0) + c
-    top = sorted(counts.items(), key=lambda kv: (-kv[1], kv[0]))[:GENRE_TILES]
+    alpha = {w: i for i, w in enumerate(sorted_words(db, list(counts), lang))}
+    top = sorted(counts.items(), key=lambda kv: (-kv[1], alpha[kv[0]]))[:GENRE_TILES]
     # A 2×2 poster collage per tile: the top movies in that genre (color hash is the client fallback).
     art = top_art_keys(
         db,

backend/app/routes/plex/people.py

@@ -7,6 +7,7 @@ from fastapi import APIRouter, BackgroundTasks, Depends
 from sqlalchemy import func, or_, select
 from sqlalchemy.orm import Session
 
+from app.collation import collated
 from app import logs
 from app.auth import current_user
 from app.db import SessionLocal, get_db
@@ -19,7 +20,7 @@ from app.models import (
 from app.plex import rollup
 from app.plex import tmdb as plex_tmdb
 from app.plex.cards import movie_card, norm_lang, show_card
-from app.plex.query import content_libs, split_csv
+from app.plex.query import content_libs, split_csv, title_col
 
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 log = logs.get_logger(__name__)
@@ -202,7 +203,9 @@ def person_detail(
                         PlexItem.directors.contains([name]),
                     ),
                 )
-                .order_by(PlexItem.year.desc().nullslast(), func.lower(PlexItem.title))
+                .order_by(
+                    PlexItem.year.desc().nullslast(), collated(title_col(PlexItem, lang), lang)
+                )
                 .limit(_PERSON_SECTION_MAX)
             )
             .scalars()
@@ -223,7 +226,9 @@ def person_detail(
                         PlexShow.directors.contains([name]),
                     ),
                 )
-                .order_by(PlexShow.year.desc().nullslast(), func.lower(PlexShow.title))
+                .order_by(
+                    PlexShow.year.desc().nullslast(), collated(title_col(PlexShow, lang), lang)
+                )
                 .limit(_PERSON_SECTION_MAX)
             )
             .scalars()

backend/tests/test_collation.py

@@ -0,0 +1,209 @@
+"""E30 S3: every A→Z list the server orders is in the reader's alphabet. The database image is Alpine,
+whose `en_US.utf8` is BYTE order: "Életrajzi" and "Ötödik" sorted after "Zorró" in the feed, the channel
+list, the Plex grid, the genre list. Hungarian puts "Ö" after "O" and "Cs" after "Cu". Needs the DB."""
+
+from fastapi.testclient import TestClient
+
+import app.state as state
+from app.auth import current_user
+from app.collation import sorted_words
+from app.db import get_db
+from app.main import app
+from app.models import (
+    Channel,
+    Playlist,
+    PlaylistItem,
+    PlexCollection,
+    PlexItem,
+    PlexLibrary,
+    Subscription,
+    User,
+    Video,
+)
+from datetime import datetime, timezone
+
+WORDS = ["Zorró", "Életrajzi", "Ötödik", "oroszlán", "Csillag", "Cukor"]
+HU = ["Cukor", "Csillag", "Életrajzi", "oroszlán", "Ötödik", "Zorró"]
+EN = ["Csillag", "Cukor", "Életrajzi", "oroszlán", "Ötödik", "Zorró"]
+
+
+def _user(db, lang: str) -> User:
+    user = User(email=f"collate-{lang}@example.com", preferences={"language": lang})
+    db.add(user)
+    db.flush()
+    return user
+
+
+def _client(db, user, monkeypatch, override_dep) -> TestClient:
+    monkeypatch.setattr(state, "_configured_cache", True)
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app)
+
+
+def test_words_sort_in_the_readers_alphabet(db):
+    assert sorted_words(db, WORDS, "hu") == HU
+    assert sorted_words(db, WORDS, "en") == EN
+    assert sorted_words(db, WORDS, "xx") == EN  # an unknown language sorts as English
+    assert sorted_words(db, [], "hu") == []
+
+
+def _seed_feed(db, user):
+    db.add(Channel(id="UCc", title="Channel"))
+    db.flush()
+    db.add(Subscription(user_id=user.id, channel_id="UCc", priority=0, hidden=False))
+    db.add_all(
+        Video(
+            id=f"v{i}",
+            channel_id="UCc",
+            published_at=datetime(2024, 1, i + 1, tzinfo=timezone.utc),
+            title=w,
+            is_short=False,
+            live_status="none",
+            via_search=False,
+            via_explore=False,
+        )
+        for i, w in enumerate(WORDS)
+    )
+    db.commit()
+
+
+def test_the_feed_title_sort_pages_in_the_readers_alphabet(db, monkeypatch, override_dep):
+    user = _user(db, "hu")
+    _seed_feed(db, user)
+    client = _client(db, user, monkeypatch, override_dep)
+
+    full = [it["title"] for it in client.get("/api/feed?sort=title&limit=50").json()["items"]]
+    assert full == HU
+    # The cursor compares with the same collated expression, so paging walks the same order.
+    walked: list[str] = []
+    cursor = None
+    for _ in range(len(WORDS)):
+        url = "/api/feed?sort=title&limit=2" + (f"&cursor={cursor}" if cursor else "")
+        body = client.get(url).json()
+        walked += [it["title"] for it in body["items"]]
+        cursor = body["next_cursor"]
+        if not body["has_more"]:
+            break
+    assert walked == HU
+    desc = client.get("/api/feed?sort=title_desc&limit=50").json()["items"]
+    assert [it["title"] for it in desc] == HU[::-1]
+
+
+def test_the_channel_list_is_in_the_readers_alphabet(db, monkeypatch, override_dep):
+    user = _user(db, "hu")
+    db.add_all(Channel(id=f"UC{i}", title=w) for i, w in enumerate(WORDS))
+    db.flush()
+    db.add_all(
+        Subscription(user_id=user.id, channel_id=f"UC{i}", priority=0, hidden=False)
+        for i in range(len(WORDS))
+    )
+    db.commit()
+    r = _client(db, user, monkeypatch, override_dep).get("/api/channels")
+    assert [c["title"] for c in r.json()] == HU
+
+
+def _seed_plex(db):
+    lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
+    db.add(lib)
+    db.flush()
+    col = PlexCollection(rating_key="col1", library_id=lib.id, title="Set", child_count=len(WORDS))
+    db.add(col)
+    db.add_all(
+        PlexItem(
+            rating_key=f"m{i}",
+            library_id=lib.id,
+            kind="movie",
+            title=f"EN {i}",
+            title_hu=w,
+            year=2000,
+            genres_hu=[w],
+            collection_keys=["col1"],
+        )
+        for i, w in enumerate(WORDS)
+    )
+    db.commit()
+
+
+def _plex(db, monkeypatch, override_dep) -> TestClient:
+    user = _user(db, "hu")
+    _seed_plex(db)
+    return _client(db, user, monkeypatch, override_dep)
+
+
+def test_the_plex_grid_sorts_by_the_hungarian_title(db, monkeypatch, override_dep):
+    client = _plex(db, monkeypatch, override_dep)
+    grid = client.get("/api/plex/library?scope=movie&sort=title&sort_dir=asc&lang=hu").json()
+    assert [it["title"] for it in grid["items"]] == HU
+
+
+def test_the_plex_genre_list_is_in_the_readers_alphabet(db, monkeypatch, override_dep):
+    client = _plex(db, monkeypatch, override_dep)
+    facets = client.get("/api/plex/facets?scope=movie&lang=hu").json()
+    assert [g["value"] for g in facets["genres"]] == HU
+
+
+def test_a_collection_sorts_by_the_hungarian_title(db, monkeypatch, override_dep):
+    client = _plex(db, monkeypatch, override_dep)
+    members = client.get("/api/plex/collections/col1?sort=title&sort_dir=asc&lang=hu").json()
+    assert [it["title"] for it in members["items"]] == HU
+    # year ties everywhere, so the default (year) order falls through to the title tiebreak
+    default = client.get("/api/plex/collections/col1?lang=hu").json()
+    assert [it["title"] for it in default["items"]] == HU
+
+
+def _seed_discovery(db, user, synced: bool):
+    """Channels the user's playlist holds one video from each, not subscribed: discovery lists them,
+    count-tied, so the title decides. `synced=False` leaves them stubs, which sends the endpoint down
+    its enrich path — the one that re-sorts in Python and has to agree with the ORDER BY."""
+    pl = Playlist(user_id=user.id, name="Mix")
+    db.add(pl)
+    db.flush()
+    stamp = datetime(2024, 1, 1, tzinfo=timezone.utc) if synced else None
+    for i, w in enumerate(WORDS):
+        db.add(Channel(id=f"UCd{i}", title=w, details_synced_at=stamp))
+        db.flush()
+        db.add(
+            Video(
+                id=f"d{i}",
+                channel_id=f"UCd{i}",
+                published_at=datetime(2024, 1, 1, tzinfo=timezone.utc),
+                title="x",
+                is_short=False,
+                live_status="none",
+                via_search=False,
+                via_explore=False,
+            )
+        )
+        db.flush()
+        db.add(PlaylistItem(playlist_id=pl.id, video_id=f"d{i}", position=i))
+    db.commit()
+
+
+def test_channel_discovery_is_in_the_readers_alphabet(db, monkeypatch, override_dep):
+    user = _user(db, "hu")
+    _seed_discovery(db, user, synced=True)
+    r = _client(db, user, monkeypatch, override_dep).get("/api/channels/discovery")
+    assert [c["title"] for c in r.json()] == HU
+
+
+def test_channel_discovery_keeps_that_order_after_enriching(db, monkeypatch, override_dep):
+    import app.routes.channels as channels
+
+    class FakeYouTube:
+        def __init__(self, *a, **k): ...
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *a):
+            return False
+
+        def get_channels(self, ids):
+            return []
+
+    monkeypatch.setattr(channels, "YouTubeClient", FakeYouTube)
+    monkeypatch.setattr(channels, "apply_channel_details", lambda *a, **k: None)
+    user = _user(db, "hu")
+    _seed_discovery(db, user, synced=False)
+    r = _client(db, user, monkeypatch, override_dep).get("/api/channels/discovery")
+    assert [c["title"] for c in r.json()] == HU