fix(db): drop 0.8 rebuild workarounds, enforce title

With sqlx 0.9 honouring `-- no-transaction`, 0007 loses its
movie_releases_backup stash like 0014 did, and 0021 gains
the CHECK (title <> '') that #153 abandoned because the 0.8
migrator could not run a rebuild with foreign keys off. The
rebuild test now enters at migration 6 so the child links
ride through all three rebuilds, and a new test proves the
'' -> 'TBA' backfill and the rejection of new empty titles.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/arr-db/migrations/0007_movie_state_canonical.sql

@@ -1,13 +1,13 @@
+-- no-transaction
 -- #73. movies.state used missing|grabbed|imported, predating arr-core's
 -- canonical MediaState vocabulary (missing|downloading|available) that
 -- series/episodes (0005) already follow.
 --
--- SQLite can't ALTER a CHECK constraint, so this rebuilds the table -- which
--- means dropping the old copy. `movie_releases` references it with
--- ON DELETE CASCADE, so the drop would take its rows down too; stash them
--- first and restore them once the new `movies` exists with the same ids.
+-- SQLite can't ALTER a CHECK constraint, so this rebuilds the table. It runs
+-- outside a transaction (#155) so `PRAGMA foreign_keys = OFF` takes effect
+-- and dropping the old `movies` does not cascade into `movie_releases`.
 
-CREATE TABLE movie_releases_backup AS SELECT * FROM movie_releases;
+PRAGMA foreign_keys = OFF;
 
 CREATE TABLE movies_new (
     id                INTEGER PRIMARY KEY,
@@ -68,6 +68,4 @@ BEGIN
     SELECT RAISE(ABORT, 'movies require a movie root');
 END;
 
-INSERT INTO movie_releases SELECT * FROM movie_releases_backup;
-
-DROP TABLE movie_releases_backup;
+PRAGMA foreign_keys = ON;

crates/arr-db/migrations/0021_episode_title_required.sql

@@ -1,11 +1,51 @@
+-- no-transaction
 -- #153. `episodes.title` accepted the empty string, which TMDB sends for an
 -- unaired episode it has not named yet. Empty titles leaked into §9.2's
 -- search haystack, §7.4 filenames and the compat shim as if they were real
 -- text. Rows already carrying `''` take the same "TBA" placeholder the TMDB
 -- boundary now substitutes — #121's guarded update replaces it once TMDB
--- fills the title in.
---
--- A hard CHECK (title <> '') would need a table rebuild with foreign_keys
--- off, which sqlx 0.8's migrator cannot run (it always wraps a migration in
--- a transaction, where that pragma is a no-op); enforcement lives in code.
+-- fills the title in — and the rebuilt table enforces non-empty with a
+-- CHECK. The rebuild runs outside a transaction (#155) so
+-- `PRAGMA foreign_keys = OFF` takes effect and dropping the old `episodes`
+-- does not cascade into `episode_releases`.
+
 UPDATE episodes SET title = 'TBA', updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now') WHERE title = '';
+
+PRAGMA foreign_keys = OFF;
+
+CREATE TABLE episodes_new (
+    id               INTEGER PRIMARY KEY,
+    season_id        INTEGER NOT NULL REFERENCES seasons (id) ON DELETE CASCADE,
+    number           INTEGER NOT NULL CHECK (number >= 0),
+    title            TEXT NOT NULL CHECK (title <> ''),
+    air_date         TEXT,
+    wanted           INTEGER NOT NULL DEFAULT 0 CHECK (wanted IN (0, 1)),
+    state            TEXT NOT NULL DEFAULT 'missing'
+                     CHECK (state IN ('missing', 'downloading', 'available', 'parked')),
+    search_attempts  INTEGER NOT NULL DEFAULT 0,
+    last_searched_at TEXT,
+    created_at       TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
+    updated_at       TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
+    vanished         INTEGER NOT NULL DEFAULT 0 CHECK (vanished IN (0, 1)),
+    UNIQUE (season_id, number)
+) STRICT;
+
+INSERT INTO episodes_new (
+    id, season_id, number, title, air_date, wanted, state, search_attempts,
+    last_searched_at, created_at, updated_at, vanished
+)
+SELECT
+    id, season_id, number, title, air_date, wanted, state, search_attempts,
+    last_searched_at, created_at, updated_at, vanished
+FROM episodes;
+
+DROP TABLE episodes;
+ALTER TABLE episodes_new RENAME TO episodes;
+
+CREATE INDEX episodes_pending_search
+    ON episodes (last_searched_at)
+    WHERE wanted = 1 AND state = 'missing';
+
+CREATE INDEX episodes_state ON episodes (state);
+
+PRAGMA foreign_keys = ON;

crates/arr-db/src/lib.rs

@@ -336,7 +336,7 @@ mod tests {
         assert_eq!(renamed_from_imported, "available");
     }
 
-    /// #155: migration 0014 rebuilds `movies` and `episodes` outside a
+    /// #155: the table-rebuild migrations (0007, 0014, 0021) run outside a
     /// transaction so `PRAGMA foreign_keys = OFF` holds and dropping the old
     /// tables does not cascade-delete `movie_releases`/`episode_releases`.
     #[tokio::test]
@@ -347,9 +347,9 @@ mod tests {
             .expect("connect");
 
         MIGRATOR
-            .run_to(13, db.pool())
+            .run_to(6, db.pool())
             .await
-            .expect("migrations before the 0014 rebuild");
+            .expect("migrations before the first rebuild");
 
         sqlx::query(
             "INSERT INTO movies (tmdb_id, title, root_id)
@@ -419,6 +419,55 @@ mod tests {
         );
     }
 
+    /// #153: an empty episode title takes the TBA placeholder during 0021's
+    /// backfill, and the rebuilt table's CHECK rejects new empty titles.
+    #[tokio::test]
+    async fn empty_episode_titles_are_backfilled_and_then_rejected() {
+        let dir = tempfile::tempdir().expect("tempdir");
+        let db = Db::connect(dir.path().join("arr.db"))
+            .await
+            .expect("connect");
+
+        MIGRATOR
+            .run_to(20, db.pool())
+            .await
+            .expect("migrations before the #153 backfill");
+
+        let series_id = sqlx::query(
+            "INSERT INTO series (tmdb_id, title, root_id)
+             SELECT 82728, 'Bluey', id FROM roots WHERE kind = 'tv' LIMIT 1",
+        )
+        .execute(db.pool())
+        .await
+        .expect("series")
+        .last_insert_rowid();
+        let season_id = sqlx::query("INSERT INTO seasons (series_id, number) VALUES (?, 1)")
+            .bind(series_id)
+            .execute(db.pool())
+            .await
+            .expect("season")
+            .last_insert_rowid();
+        sqlx::query("INSERT INTO episodes (season_id, number, title) VALUES (?, 1, '')")
+            .bind(season_id)
+            .execute(db.pool())
+            .await
+            .expect("empty title, valid before 0021");
+
+        db.migrate().await.expect("remaining migrations");
+
+        let title: String = sqlx::query_scalar("SELECT title FROM episodes")
+            .fetch_one(db.pool())
+            .await
+            .expect("episode row survives the rebuild");
+        assert_eq!(title, "TBA");
+
+        sqlx::query("INSERT INTO episodes (season_id, number, title) VALUES (?, 2, '')")
+            .bind(season_id)
+            .execute(db.pool())
+            .await
+            .expect_err("the rebuilt column rejects the empty string");
+    }
+
     #[tokio::test]
     async fn seeds_two_tv_roots_with_distinct_policies() {
         let (_dir, db) = fresh().await;