feat(club): persist active home/away kit assignments

Kits are ownership-backed club items: the owned instance stays in the
generic owned_cards inventory and only the two active roles get their own
table. This mirrors the squad_managers precedent and keeps every
FIFA-specific resourceId/wire concern in the game adapter.

* migration 0024: club_kit_assignments(club_id, slot, owned_card_id) with a
  UNIQUE owned_card_id (one instance cannot hold both roles) and
  ON DELETE CASCADE from owned_cards so a quick-sell clears the role.
* a BEFORE UPDATE OF club_id trigger clears the designation on a market
  transfer, which moves ownership by UPDATE and so is not covered by the
  cascade.
* set_active_club_kits replaces BOTH slots in one transaction, rejects
  home == away, and validates each instance against current club ownership,
  so a half-applied or dangling designation is not representable.
* get_active_club_kits revalidates ownership on read, so a stale row can
  never surface another club's item.
* GET/PUT /club/kits expose the pair.

Tests cover restart persistence, replace/clear without duplicates, atomic
rejection of invalid references, and clearing via delete and transfer.

src/app.rs

@@ -172,6 +172,8 @@ pub async fn build(pool: Pool, cfg: Config) -> Result<Router> {
         // ClubB: squad manager assignment (append-only; own lines).
         .route("/club/manager", get(routes::club::get_squad_manager))
         .route("/club/manager", put(routes::club::put_squad_manager))
+        .route("/club/kits", get(routes::club::get_active_kits))
+        .route("/club/kits", put(routes::club::put_active_kits))
         .route("/cards", get(routes::cards::get_cards))
         .route("/cards/:card_id", get(routes::cards::get_card))
         .route("/collection", get(routes::cards::get_collection))

src/routes/club.rs

@@ -163,3 +163,40 @@ pub async fn put_squad_manager(
     let manager = club_svc::get_squad_manager(&state.pool, &club.id).await?;
     Ok(Json(json!({ "manager": manager })))
 }
+
+/// Return the club's ownership-backed active home/away kit assignments.
+pub async fn get_active_kits(
+    State(state): State<AppState>,
+    game: GameId,
+) -> AppResult<Json<Value>> {
+    let profile = profile_svc::get_active_profile(&state.pool, game.as_str()).await?;
+    let club = club_svc::get_club_by_profile(&state.pool, &profile.id).await?;
+    let kits = club_svc::get_active_club_kits(&state.pool, &club.id).await?;
+    Ok(Json(json!({ "home": kits.home, "away": kits.away })))
+}
+
+#[derive(Deserialize)]
+pub struct SetActiveKitsRequest {
+    pub home_owned_card_id: Option<String>,
+    pub away_owned_card_id: Option<String>,
+}
+
+/// Atomically replace both active kit assignments. Core enforces ownership and
+/// distinct instances; game adapters enforce their own definition taxonomy.
+pub async fn put_active_kits(
+    State(state): State<AppState>,
+    game: GameId,
+    Json(req): Json<SetActiveKitsRequest>,
+) -> AppResult<Json<Value>> {
+    let profile = profile_svc::get_active_profile(&state.pool, game.as_str()).await?;
+    let club = club_svc::get_club_by_profile(&state.pool, &profile.id).await?;
+    club_svc::set_active_club_kits(
+        &state.pool,
+        &club.id,
+        req.home_owned_card_id.as_deref(),
+        req.away_owned_card_id.as_deref(),
+    )
+    .await?;
+    let kits = club_svc::get_active_club_kits(&state.pool, &club.id).await?;
+    Ok(Json(json!({ "home": kits.home, "away": kits.away })))
+}

src/services/club.rs

@@ -240,6 +240,94 @@ pub async fn clear_squad_manager(pool: &Pool, club_id: &str) -> AppResult<()> {
     Ok(())
 }
 
+// ───────────────────────── active club kits ────────────────────────────────
+
+/// The ownership-backed home and away kit assignments for one club.
+#[derive(Debug, Clone, Default)]
+pub struct ActiveClubKits {
+    pub home: Option<OwnedCard>,
+    pub away: Option<OwnedCard>,
+}
+
+async fn get_club_kit_slot(pool: &Pool, club_id: &str, slot: &str) -> AppResult<Option<OwnedCard>> {
+    Ok(sqlx::query_as::<_, OwnedCard>(&format!(
+        "{OWNED_SELECT} WHERE id = ( \
+         SELECT owned_card_id FROM club_kit_assignments WHERE club_id = ? AND slot = ? \
+         ) AND club_id = ?"
+    ))
+    .bind(club_id)
+    .bind(slot)
+    .bind(club_id)
+    .fetch_optional(pool)
+    .await?)
+}
+
+/// Read both active kit roles. Each assignment is revalidated against current
+/// ownership, so a stale/corrupt row never surfaces another club's item.
+pub async fn get_active_club_kits(pool: &Pool, club_id: &str) -> AppResult<ActiveClubKits> {
+    Ok(ActiveClubKits {
+        home: get_club_kit_slot(pool, club_id, "home").await?,
+        away: get_club_kit_slot(pool, club_id, "away").await?,
+    })
+}
+
+/// Atomically replace both active kit roles. Core enforces generic ownership and
+/// distinct-instance invariants; the game adapter validates that each definition
+/// is a kit before asking Core to assign it.
+pub async fn set_active_club_kits(
+    pool: &Pool,
+    club_id: &str,
+    home_owned_card_id: Option<&str>,
+    away_owned_card_id: Option<&str>,
+) -> AppResult<()> {
+    if home_owned_card_id.is_some() && home_owned_card_id == away_owned_card_id {
+        return Err(AppError::BadRequest(
+            "home and away kits must be different owned items".into(),
+        ));
+    }
+
+    let mut tx = pool.begin().await?;
+    for owned_card_id in [home_owned_card_id, away_owned_card_id]
+        .into_iter()
+        .flatten()
+    {
+        let owned = sqlx::query_scalar::<_, String>(
+            "SELECT id FROM owned_cards WHERE id = ? AND club_id = ?",
+        )
+        .bind(owned_card_id)
+        .bind(club_id)
+        .fetch_optional(&mut *tx)
+        .await?;
+        if owned.is_none() {
+            return Err(AppError::NotFound(format!(
+                "owned card '{owned_card_id}' not found"
+            )));
+        }
+    }
+
+    sqlx::query("DELETE FROM club_kit_assignments WHERE club_id = ?")
+        .bind(club_id)
+        .execute(&mut *tx)
+        .await?;
+    let now = Utc::now().to_rfc3339();
+    for (slot, owned_card_id) in [("home", home_owned_card_id), ("away", away_owned_card_id)] {
+        if let Some(owned_card_id) = owned_card_id {
+            sqlx::query(
+                "INSERT INTO club_kit_assignments \
+                 (club_id, slot, owned_card_id, updated_at) VALUES (?, ?, ?, ?)",
+            )
+            .bind(club_id)
+            .bind(slot)
+            .bind(owned_card_id)
+            .bind(&now)
+            .execute(&mut *tx)
+            .await?;
+        }
+    }
+    tx.commit().await?;
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -247,8 +335,7 @@ mod tests {
 
     const TS: &str = "2026-01-01T00:00:00Z";
 
-    /// A file-backed pool (so a "restart" can reopen the same DB) with two clubs:
-    /// club-a owns `mgr` + `mgr2` + `player`, club-b owns `foreign`.
+    /// A file-backed pool (so a "restart" can reopen the same DB) with two clubs.
     async fn fixture() -> (tempfile::TempDir, String, db::Pool) {
         let dir = tempfile::tempdir().expect("tempdir");
         let url = format!("sqlite://{}", dir.path().join("core.db").display());
@@ -270,14 +357,17 @@ mod tests {
                 .bind(club).bind(profile).bind(club).bind(1000i64).bind(TS).bind(TS)
                 .execute(&pool).await.expect("club");
         }
-        for (id, club) in [
-            ("mgr", "club-a"),
-            ("mgr2", "club-a"),
-            ("player", "club-a"),
-            ("foreign", "club-b"),
+        for (id, club, definition) in [
+            ("mgr", "club-a", "def-mgr"),
+            ("mgr2", "club-a", "def-mgr"),
+            ("player", "club-a", "def-player"),
+            ("kit-home", "club-a", "def-kit-home"),
+            ("kit-away", "club-a", "def-kit-away"),
+            ("kit-away-2", "club-a", "def-kit-away-2"),
+            ("foreign", "club-b", "def-kit-foreign"),
         ] {
             sqlx::query("INSERT INTO owned_cards (id, club_id, card_id, is_loan, acquired_at) VALUES (?, ?, ?, 0, ?)")
-                .bind(id).bind(club).bind("def-mgr").bind(TS)
+                .bind(id).bind(club).bind(definition).bind(TS)
                 .execute(&pool).await.expect("owned card");
         }
         // club-a has one squad.
@@ -293,6 +383,13 @@ mod tests {
             .unwrap()
     }
 
+    async fn kit_rows(pool: &db::Pool) -> i64 {
+        sqlx::query_scalar::<_, i64>("SELECT COUNT(*) FROM club_kit_assignments")
+            .fetch_one(pool)
+            .await
+            .unwrap()
+    }
+
     #[tokio::test]
     async fn manager_persists_across_reload_and_restart() {
         let (dir, url, pool) = fixture().await;
@@ -366,4 +463,96 @@ mod tests {
         let (_dir, _url, pool) = fixture().await;
         assert!(get_squad_manager(&pool, "club-a").await.unwrap().is_none());
     }
+    #[tokio::test]
+    async fn kits_persist_across_reload_and_restart() {
+        let (dir, url, pool) = fixture().await;
+        set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-away"))
+            .await
+            .expect("assign kits");
+        let current = get_active_club_kits(&pool, "club-a").await.unwrap();
+        assert_eq!(
+            current.home.as_ref().map(|item| item.id.as_str()),
+            Some("kit-home")
+        );
+        assert_eq!(
+            current.away.as_ref().map(|item| item.id.as_str()),
+            Some("kit-away")
+        );
+
+        pool.close().await;
+        let reopened = db::init_pool(&url, 5).await.expect("reopen");
+        db::run_migrations(&reopened).await.expect("migrations");
+        let persisted = get_active_club_kits(&reopened, "club-a").await.unwrap();
+        assert_eq!(persisted.home.map(|item| item.id), Some("kit-home".into()));
+        assert_eq!(persisted.away.map(|item| item.id), Some("kit-away".into()));
+        drop(dir);
+    }
+
+    #[tokio::test]
+    async fn kits_replace_clear_and_never_duplicate() {
+        let (_dir, _url, pool) = fixture().await;
+        set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-away"))
+            .await
+            .unwrap();
+        set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-away-2"))
+            .await
+            .unwrap();
+        assert_eq!(kit_rows(&pool).await, 2);
+        let current = get_active_club_kits(&pool, "club-a").await.unwrap();
+        assert_eq!(current.away.map(|item| item.id), Some("kit-away-2".into()));
+
+        set_active_club_kits(&pool, "club-a", None, None)
+            .await
+            .unwrap();
+        assert_eq!(kit_rows(&pool).await, 0);
+    }
+
+    #[tokio::test]
+    async fn kits_reject_invalid_references_atomically() {
+        let (_dir, _url, pool) = fixture().await;
+        set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-away"))
+            .await
+            .unwrap();
+
+        assert!(set_active_club_kits(&pool, "club-a", Some("foreign"), None)
+            .await
+            .is_err());
+        assert!(
+            set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-home"))
+                .await
+                .is_err()
+        );
+
+        let unchanged = get_active_club_kits(&pool, "club-a").await.unwrap();
+        assert_eq!(unchanged.home.map(|item| item.id), Some("kit-home".into()));
+        assert_eq!(unchanged.away.map(|item| item.id), Some("kit-away".into()));
+        assert_eq!(kit_rows(&pool).await, 2);
+    }
+
+    #[tokio::test]
+    async fn kit_delete_and_transfer_clear_active_designations() {
+        let (_dir, _url, pool) = fixture().await;
+        set_active_club_kits(&pool, "club-a", Some("kit-home"), Some("kit-away"))
+            .await
+            .unwrap();
+
+        sqlx::query("DELETE FROM owned_cards WHERE id = 'kit-home'")
+            .execute(&pool)
+            .await
+            .expect("quick sell kit");
+        let after_delete = get_active_club_kits(&pool, "club-a").await.unwrap();
+        assert!(after_delete.home.is_none());
+        assert_eq!(
+            after_delete.away.map(|item| item.id),
+            Some("kit-away".into())
+        );
+
+        sqlx::query("UPDATE owned_cards SET club_id = 'club-b' WHERE id = 'kit-away'")
+            .execute(&pool)
+            .await
+            .expect("transfer kit");
+        assert_eq!(kit_rows(&pool).await, 0);
+        let after_transfer = get_active_club_kits(&pool, "club-a").await.unwrap();
+        assert!(after_transfer.home.is_none() && after_transfer.away.is_none());
+    }
 }