Initial commit: OpenFUT Core

Offline Ultimate Team backend — game-independent REST API.

- 19 API endpoints: auth, profiles, clubs, cards, packs, squads,
  objectives, SBCs, match rewards, NPC market, statistics
- Axum + SQLite + SQLx with full migrations
- Weighted pack generator, SBC validation engine
- JSON-driven mod data (cards, packs, objectives, SBCs)
- 5 integration tests passing

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

src/services/profile.rs

@@ -0,0 +1,52 @@
+use crate::{
+    db::Pool,
+    error::{AppError, AppResult},
+    models::profile::Profile,
+};
+use chrono::Utc;
+
+pub async fn get_active_profile(pool: &Pool) -> AppResult<Profile> {
+    sqlx::query_as::<_, Profile>(
+        "SELECT id, username, level, xp, created_at, updated_at FROM profiles ORDER BY created_at ASC LIMIT 1"
+    )
+    .fetch_optional(pool)
+    .await?
+    .ok_or_else(|| AppError::NotFound("no profile exists; call POST /auth/local first".into()))
+}
+
+pub async fn create_profile(pool: &Pool, username: &str) -> AppResult<Profile> {
+    let existing = sqlx::query_scalar::<_, i64>("SELECT COUNT(*) FROM profiles")
+        .fetch_one(pool)
+        .await?;
+    if existing > 0 {
+        return Err(AppError::Conflict(
+            "a profile already exists; OpenFUT is single-player only".into(),
+        ));
+    }
+
+    let profile = Profile::new(username);
+    sqlx::query(
+        "INSERT INTO profiles (id, username, level, xp, created_at, updated_at) VALUES (?, ?, ?, ?, ?, ?)"
+    )
+    .bind(&profile.id)
+    .bind(&profile.username)
+    .bind(profile.level)
+    .bind(profile.xp)
+    .bind(profile.created_at)
+    .bind(profile.updated_at)
+    .execute(pool)
+    .await?;
+
+    Ok(profile)
+}
+
+pub async fn add_xp(pool: &Pool, profile_id: &str, xp: i64) -> AppResult<()> {
+    let now = Utc::now();
+    sqlx::query("UPDATE profiles SET xp = xp + ?, updated_at = ? WHERE id = ?")
+        .bind(xp)
+        .bind(now)
+        .bind(profile_id)
+        .execute(pool)
+        .await?;
+    Ok(())
+}