Phase 10: card upgrade system (chemistry styles, position change, training)

- GET /chemistry-styles — lists 18 FUT-style chemistry styles with stat boost breakdowns
- POST /collection/:id/chemistry-style — apply a style (Shadow, Hunter, Anchor, etc.)
- POST /collection/:id/position — override a player's position for 500 coins
- POST /collection/:id/training — add +1/+2/+3 OVR training bonus (max +3 total)
- GET /collection now includes chemistry_style, position_override, training_bonus,
  effective_overall and effective_position fields per owned card
- Migration 0007 adds three columns to owned_cards with safe defaults
- 10 new integration tests — all 55 pass, clippy clean

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/cards.rs

@@ -98,7 +98,7 @@ pub async fn get_collection(State(state): State<AppState>) -> AppResult<Json<Val
     let club = club_svc::get_club_by_profile(&state.pool, &profile.id).await?;
 
     let owned = sqlx::query_as::<_, OwnedCard>(
-        "SELECT id, club_id, card_id, is_loan, loan_matches_remaining, acquired_at FROM owned_cards WHERE club_id = ?"
+        "SELECT id, club_id, card_id, is_loan, loan_matches_remaining, acquired_at, chemistry_style, position_override, training_bonus FROM owned_cards WHERE club_id = ?"
     )
     .bind(&club.id)
     .fetch_all(&state.pool)
@@ -108,11 +108,19 @@ pub async fn get_collection(State(state): State<AppState>) -> AppResult<Json<Val
         .iter()
         .filter_map(|o| {
             state.card_db.get(&o.card_id).map(|def| {
+                let effective_overall = def.overall as i64 + o.training_bonus;
+                let effective_position =
+                    o.position_override.as_deref().unwrap_or(&def.position);
                 json!({
                     "owned_card_id": o.id,
                     "is_loan": o.is_loan,
                     "loan_matches_remaining": o.loan_matches_remaining,
                     "acquired_at": o.acquired_at,
+                    "chemistry_style": o.chemistry_style,
+                    "position_override": o.position_override,
+                    "training_bonus": o.training_bonus,
+                    "effective_overall": effective_overall,
+                    "effective_position": effective_position,
                     "card": def,
                 })
             })
@@ -133,7 +141,8 @@ pub async fn delete_owned_card(
     let club = club_svc::get_club_by_profile(&state.pool, &profile.id).await?;
 
     let owned = sqlx::query_as::<_, OwnedCard>(
-        "SELECT id, club_id, card_id, is_loan, loan_matches_remaining, acquired_at \
+        "SELECT id, club_id, card_id, is_loan, loan_matches_remaining, acquired_at, \
+         chemistry_style, position_override, training_bonus \
          FROM owned_cards WHERE id = ? AND club_id = ?",
     )
     .bind(&owned_card_id)