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/models/profile.rs

@@ -0,0 +1,32 @@
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
+pub struct Profile {
+    pub id: String,
+    pub username: String,
+    pub level: i64,
+    pub xp: i64,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+impl Profile {
+    pub fn new(username: impl Into<String>) -> Self {
+        let now = Utc::now();
+        Self {
+            id: Uuid::new_v4().to_string(),
+            username: username.into(),
+            level: 1,
+            xp: 0,
+            created_at: now,
+            updated_at: now,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+pub struct CreateProfileRequest {
+    pub username: Option<String>,
+}