fix(meta): store unrated titles as NULL, not zero

TMDB reports vote_average: 0 where no rating exists (#156). Normalise
it to None at the arr-meta edge, like non_empty does for "", and let
the Option flow through the daemon refresh and API add paths so the
nullable columns from #145 do their job.

crates/arr-api/src/movies.rs

@@ -316,7 +316,7 @@ pub async fn create(
     let artwork = lookup_movie_artwork(&state, input.tmdb_id).await;
     let poster_path = artwork.as_ref().and_then(|a| a.0.clone());
     let backdrop_path = artwork.as_ref().and_then(|a| a.1.clone());
-    let vote_average = artwork.as_ref().map(|a| a.2);
+    let vote_average = artwork.as_ref().and_then(|a| a.2);
     let result = sqlx::query!(
         "INSERT INTO movies (tmdb_id, title, year, original_language, root_id, wanted, blocked, overrides, poster_path, backdrop_path, vote_average) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
         input.tmdb_id, title, input.year, input.original_language, input.root_id,
@@ -336,7 +336,7 @@ pub async fn create(
 async fn lookup_movie_artwork(
     state: &AppState,
     tmdb_id: i64,
-) -> Option<(Option<String>, Option<String>, f64)> {
+) -> Option<(Option<String>, Option<String>, Option<f64>)> {
     let client = crate::search::tmdb_client(state).ok()?;
     let movie = client.movie(u32::try_from(tmdb_id).ok()?).await.ok()?;
     Some((movie.poster_path, movie.backdrop_path, movie.vote_average))

crates/arr-api/src/series.rs

@@ -445,7 +445,7 @@ pub async fn create(
     let tvdb_id = tmdb_series.as_ref().and_then(|s| s.tvdb_id).map(i64::from);
     let poster_path = tmdb_series.as_ref().and_then(|s| s.poster_path.clone());
     let backdrop_path = tmdb_series.as_ref().and_then(|s| s.backdrop_path.clone());
-    let vote_average = tmdb_series.as_ref().map(|s| s.vote_average);
+    let vote_average = tmdb_series.as_ref().and_then(|s| s.vote_average);
     let result = sqlx::query!(
         "INSERT INTO series (tmdb_id, tvdb_id, title, year, original_language, root_id, auto_track, upstream_ended, blocked, overrides, poster_path, backdrop_path, vote_average) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
         input.tmdb_id, tvdb_id, title, input.year, input.original_language, input.root_id,

crates/arr-daemon/src/grab.rs

@@ -2497,6 +2497,81 @@ mod tests {
         assert_eq!(unchanged, (poster, backdrop, vote));
     }
 
+    /// TMDB reports `vote_average: 0` for a title nobody has rated — absence,
+    /// not zero (#156). It must store as NULL, be overwritten when votes
+    /// arrive, and go back to NULL if they are withdrawn.
+    #[tokio::test]
+    async fn metadata_refresh_stores_an_unrated_title_as_null() {
+        let (_dir, database) = wanted_movie().await;
+        let indexer = empty_prowlarr().await;
+        let unrated = || {
+            RELEASED_METADATA.replace(
+                r#""original_language": "en","#,
+                r#""original_language": "en",
+                  "poster_path": "/dune-two.jpg",
+                  "backdrop_path": "/dune-two-wide.jpg",
+                  "vote_average": 0.0,"#,
+            )
+        };
+        let rated = || {
+            RELEASED_METADATA.replace(
+                r#""original_language": "en","#,
+                r#""original_language": "en",
+                  "poster_path": "/dune-two.jpg",
+                  "backdrop_path": "/dune-two-wide.jpg",
+                  "vote_average": 8.152,"#,
+            )
+        };
+        let (downloader, _fake) = transmission().await;
+
+        action_with_tmdb(&indexer, &downloader, &tmdb(&unrated()).await)
+            .tick(&database)
+            .await
+            .unwrap();
+        let vote: Option<f64> =
+            sqlx::query_scalar("SELECT vote_average FROM movies WHERE tmdb_id IS NOT NULL")
+                .fetch_one(database.pool())
+                .await
+                .unwrap();
+        assert_eq!(vote, None);
+
+        // Votes arrive: the NULL is overwritten.
+        sqlx::query(
+            "UPDATE movies SET metadata_refreshed_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now', '-7 hours')",
+        )
+        .execute(database.pool())
+        .await
+        .unwrap();
+        action_with_tmdb(&indexer, &downloader, &tmdb(&rated()).await)
+            .tick(&database)
+            .await
+            .unwrap();
+        let vote: Option<f64> =
+            sqlx::query_scalar("SELECT vote_average FROM movies WHERE tmdb_id IS NOT NULL")
+                .fetch_one(database.pool())
+                .await
+                .unwrap();
+        assert_eq!(vote, Some(8.152));
+
+        // And withdrawn again.
+        sqlx::query(
+            "UPDATE movies SET metadata_refreshed_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now', '-7 hours')",
+        )
+        .execute(database.pool())
+        .await
+        .unwrap();
+        action_with_tmdb(&indexer, &downloader, &tmdb(&unrated()).await)
+            .tick(&database)
+            .await
+            .unwrap();
+        let vote: Option<f64> =
+            sqlx::query_scalar("SELECT vote_average FROM movies WHERE tmdb_id IS NOT NULL")
+                .fetch_one(database.pool())
+                .await
+                .unwrap();
+        assert_eq!(vote, None);
+    }
+
     #[tokio::test]
     async fn metadata_changes_reset_a_title_backoff() {
         let (_dir, database) = wanted_movie().await;

crates/arr-daemon/src/series_refresh.rs

@@ -232,7 +232,7 @@ impl SeriesRefreshAction {
         let backdrop_path_ref = backdrop_path.as_deref();
         let artwork_moved =
             stale.poster_path != poster_path || stale.backdrop_path != backdrop_path;
-        if artwork_moved || stale.vote_average != Some(vote_average) {
+        if artwork_moved || stale.vote_average != vote_average {
             sqlx::query!(
                 "UPDATE series SET poster_path = ?, backdrop_path = ?, vote_average = ?,
                                         updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now')

crates/arr-meta/src/model.rs

@@ -82,8 +82,10 @@ pub struct Movie {
     /// Path fragment, not a URL. §9.6 stores this on the row alongside
     /// [`Movie::poster_path`] and `vote_average`.
     pub backdrop_path: Option<String>,
-    /// TMDB's rating, out of 10. Stored with the artwork (§9.6).
+    /// TMDB's rating, out of 10, when TMDB has votes for it. Stored with the
-    pub vote_average: f64,
+    /// artwork (§9.6). TMDB sends `0` where "no rating yet" is meant, so a
+    /// zero rating is normalised away here rather than stored as one.
+    pub vote_average: Option<f64>,
 }
 
 impl Movie {
@@ -136,8 +138,9 @@ pub struct Series {
     /// §9.6 stores this on the row alongside `poster_path` and
     /// [`Series::vote_average`].
     pub backdrop_path: Option<String>,
-    /// TMDB's rating, out of 10. Stored with the artwork (§9.6).
+    /// TMDB's rating, out of 10, when TMDB has votes for it. Stored with the
-    pub vote_average: f64,
+    /// artwork (§9.6); zero is normalised away like [`Movie::vote_average`].
+    pub vote_average: Option<f64>,
     pub seasons: Vec<SeasonSummary>,
 }
 
@@ -372,7 +375,7 @@ impl From<RawSeries> for Series {
             overview: non_empty(raw.overview),
             poster_path: non_empty(raw.poster_path),
             backdrop_path: non_empty(raw.backdrop_path),
-            vote_average: raw.vote_average,
+            vote_average: rating(raw.vote_average),
             seasons: raw
                 .seasons
                 .into_iter()
@@ -562,7 +565,7 @@ impl From<RawMovie> for Movie {
             overview: non_empty(raw.overview),
             poster_path: non_empty(raw.poster_path),
             backdrop_path: non_empty(raw.backdrop_path),
-            vote_average: raw.vote_average,
+            vote_average: rating(raw.vote_average),
         }
     }
 }
@@ -596,6 +599,12 @@ fn non_empty(value: Option<String>) -> Option<String> {
     value.filter(|text| !text.is_empty())
 }
 
+/// TMDB uses `0` where "no votes yet" is meant, so an unrated title never
+/// carries a rating rather than carrying zero.
+fn rating(value: f64) -> Option<f64> {
+    (value != 0.0).then_some(value)
+}
+
 #[derive(Debug, Deserialize)]
 pub(crate) struct RawMovieDetail {
     id: u32,

crates/arr-meta/tests/tmdb.rs

@@ -217,6 +217,9 @@ async fn unreleased_movie_has_no_dates_and_no_imdb_id() {
     assert_eq!(movie.imdb_id, None);
     assert_eq!(movie.runtime, None);
     assert!(movie.origin_countries.is_empty());
+    // TMDB reports vote_average: 0 for an unrated title — absence, not zero
+    // (#156), so it is normalised away like any other zero-valued null.
+    assert_eq!(movie.vote_average, None);
     assert!(!movie.is_digitally_released(date(2026, 8, 22)));
 }