style(core): apply cargo fmt across routes, services, models, tests

Pure rustfmt reflow (import grouping, array/match-arm/call-arg wrapping,
alphabetized module decls, comment realignment). No semantic change:
full-diff and `git diff -w` both confirm logic byte-identical to 271c363;
workspace builds and all 74 core tests pass. Retained pre-existing WIP
brought forward after verification.

src/routes/cards.rs

@@ -11,8 +11,7 @@ use crate::{
     error::{AppError, AppResult},
     models::card::OwnedCard,
     services::{
-        club as club_svc,
-        economy as economy_svc,
+        club as club_svc, economy as economy_svc,
         inventory::{self, OwnedItemQuery, OwnedItemView},
         profile as profile_svc,
     },
@@ -20,11 +19,17 @@ use crate::{
 
 /// Quick-sell value for a card based on overall rating.
 fn quick_sell_coins(overall: u8) -> i64 {
-    if overall >= 85 { 1500 }
-    else if overall >= 80 { 900 }
-    else if overall >= 75 { 600 }
-    else if overall >= 65 { 300 }
-    else { 150 }
+    if overall >= 85 {
+        1500
+    } else if overall >= 80 {
+        900
+    } else if overall >= 75 {
+        600
+    } else if overall >= 65 {
+        300
+    } else {
+        150
+    }
 }
 
 #[derive(Debug, Deserialize)]
@@ -96,7 +101,9 @@ pub async fn get_cards(
         cards.truncate(limit);
     }
 
-    Ok(Json(json!({ "cards": cards, "total": total, "returned": cards.len() })))
+    Ok(Json(
+        json!({ "cards": cards, "total": total, "returned": cards.len() }),
+    ))
 }
 
 pub async fn get_collection(
@@ -119,8 +126,7 @@ pub async fn get_collection(
         .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);
+                let effective_position = o.position_override.as_deref().unwrap_or(&def.position);
                 let body = json!({
                     "owned_card_id": o.id,
                     "is_loan": o.is_loan,
@@ -178,10 +184,9 @@ pub async fn delete_owned_card(
     .await?
     .ok_or_else(|| AppError::NotFound(format!("owned card '{owned_card_id}' not found")))?;
 
-    let card = state
-        .card_db
-        .get(&owned.card_id)
-        .ok_or_else(|| AppError::NotFound(format!("card definition '{}' missing", owned.card_id)))?;
+    let card = state.card_db.get(&owned.card_id).ok_or_else(|| {
+        AppError::NotFound(format!("card definition '{}' missing", owned.card_id))
+    })?;
 
     let coins = quick_sell_coins(card.overall);