M1/#292: core library migration (artists/albums/tracks/users)

internal/db/migrations/0002_core_library.up.sql

@@ -0,0 +1,60 @@
+-- Core library schema per spec §5. Dual-like, session, scrobble, and
+-- similarity tables land with their respective feature milestones.
+
+CREATE EXTENSION IF NOT EXISTS "pgcrypto";
+
+CREATE TABLE artists (
+    id         uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+    name       text NOT NULL,
+    sort_name  text NOT NULL,
+    mbid       text,
+    created_at timestamptz NOT NULL DEFAULT now(),
+    updated_at timestamptz NOT NULL DEFAULT now()
+);
+CREATE UNIQUE INDEX artists_mbid_unique ON artists (mbid) WHERE mbid IS NOT NULL;
+CREATE INDEX artists_sort_name ON artists (sort_name);
+
+CREATE TABLE albums (
+    id             uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+    title          text NOT NULL,
+    sort_title     text NOT NULL,
+    artist_id      uuid NOT NULL REFERENCES artists (id) ON DELETE CASCADE,
+    release_date   date,
+    mbid           text,
+    cover_art_path text,
+    created_at     timestamptz NOT NULL DEFAULT now(),
+    updated_at     timestamptz NOT NULL DEFAULT now()
+);
+CREATE UNIQUE INDEX albums_mbid_unique ON albums (mbid) WHERE mbid IS NOT NULL;
+CREATE INDEX albums_artist ON albums (artist_id);
+CREATE INDEX albums_sort_title ON albums (sort_title);
+
+CREATE TABLE tracks (
+    id           uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+    title        text NOT NULL,
+    album_id     uuid NOT NULL REFERENCES albums (id) ON DELETE CASCADE,
+    artist_id    uuid NOT NULL REFERENCES artists (id) ON DELETE CASCADE,
+    track_number integer,
+    disc_number  integer,
+    duration_ms  integer NOT NULL,
+    file_path    text NOT NULL UNIQUE,
+    file_size    bigint NOT NULL,
+    file_format  text NOT NULL,
+    bitrate      integer,
+    mbid         text,
+    genre        text,
+    added_at     timestamptz NOT NULL DEFAULT now(),
+    updated_at   timestamptz NOT NULL DEFAULT now()
+);
+CREATE UNIQUE INDEX tracks_mbid_unique ON tracks (mbid) WHERE mbid IS NOT NULL;
+CREATE INDEX tracks_album ON tracks (album_id, disc_number, track_number);
+CREATE INDEX tracks_artist ON tracks (artist_id);
+
+CREATE TABLE users (
+    id            uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+    username      text NOT NULL UNIQUE,
+    password_hash text NOT NULL,
+    api_token     text NOT NULL UNIQUE,
+    is_admin      boolean NOT NULL DEFAULT false,
+    created_at    timestamptz NOT NULL DEFAULT now()
+);