feat(db): season_releases table and season policy loader

crates/arr-db/migrations/0017_season_releases.sql

@@ -0,0 +1,10 @@
+-- The season counterpart of episode_releases (0006). A targeted season search
+-- returns packs the operator has not committed to, which is the wrong grain
+-- for a table that links a release to one episode (DESIGN.md §9.3, issue 125).
+CREATE TABLE season_releases (
+    season_id INTEGER NOT NULL REFERENCES seasons (id) ON DELETE CASCADE,
+    release_id INTEGER NOT NULL REFERENCES releases (id) ON DELETE CASCADE,
+    PRIMARY KEY (season_id, release_id)
+) STRICT;
+
+CREATE INDEX season_releases_release ON season_releases (release_id);

crates/arr-db/src/policy.rs

@@ -275,6 +275,75 @@ impl Db {
             root_path: row.root_path,
         }))
     }
+
+    /// The policy attached to a season's series root, with that series'
+    /// overrides. Same rule as [`Db::episode_policy`]: overrides sit on the
+    /// series (§5.1), never on a season.
+    ///
+    /// `None` when the season does not exist.
+    ///
+    /// # Errors
+    ///
+    /// If the query fails, or a policy column does not hold the JSON its
+    /// migration promises.
+    pub async fn season_policy(&self, season_id: i64) -> Result<Option<TitlePolicy>, PolicyError> {
+        let row = sqlx::query!(
+            r#"
+            SELECT   s.overrides       AS "overrides!: String",
+                     r.id              AS "root_id!: i64",
+                     r.kind            AS "root_kind!: String",
+                     r.audience        AS "root_audience!: String",
+                     r.path            AS "root_path!: String",
+                     p.id              AS "policy_id!: i64",
+                     p.name            AS "policy_name!: String",
+                     p.required_audio  AS "required_audio!: String",
+                     p.dub_blacklist   AS "dub_blacklist!: String",
+                     p.hdr_rules       AS "hdr_rules!: String",
+                     p.size_bands      AS "size_bands!: String",
+                     p.resolution_pref AS "resolution_pref!: String",
+                     p.source_weights  AS "source_weights!: String",
+                     p.score_weights   AS "score_weights!: String"
+            FROM     seasons se
+            JOIN     series s    ON s.id = se.series_id
+            JOIN     roots r     ON r.id = s.root_id
+            JOIN     policies p  ON p.id = r.policy_id
+            WHERE    se.id = ?
+            "#,
+            season_id
+        )
+        .fetch_optional(self.pool())
+        .await?;
+
+        let Some(row) = row else {
+            return Ok(None);
+        };
+
+        let overrides: OverridesJson = json("overrides", &row.overrides)?;
+        let policy = PolicyColumns {
+            id: row.policy_id,
+            name: row.policy_name,
+            required_audio: row.required_audio,
+            dub_blacklist: row.dub_blacklist,
+            hdr_rules: row.hdr_rules,
+            size_bands: row.size_bands,
+            resolution_pref: row.resolution_pref,
+            source_weights: row.source_weights,
+            score_weights: row.score_weights,
+        }
+        .to_policy()?;
+
+        Ok(Some(TitlePolicy {
+            policy,
+            overrides: TitleOverrides {
+                only_4k: overrides.only_4k,
+                allow_english_audio: overrides.allow_english_audio,
+            },
+            root_id: row.root_id,
+            root_kind: row.root_kind,
+            root_audience: row.root_audience,
+            root_path: row.root_path,
+        }))
+    }
 }
 
 /// A BCP-47 tag as the policy columns write it.