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/config.rs

@@ -0,0 +1,25 @@
+use anyhow::Result;
+
+#[derive(Debug, Clone)]
+pub struct Config {
+    pub listen_addr: String,
+    pub database_url: String,
+    pub data_dir: String,
+    #[allow(dead_code)]
+    pub max_connections: u32,
+}
+
+impl Config {
+    pub fn from_env() -> Result<Self> {
+        Ok(Self {
+            listen_addr: std::env::var("LISTEN_ADDR").unwrap_or_else(|_| "127.0.0.1:8080".into()),
+            database_url: std::env::var("DATABASE_URL")
+                .unwrap_or_else(|_| "sqlite://openfut.db".into()),
+            data_dir: std::env::var("DATA_DIR").unwrap_or_else(|_| "data".into()),
+            max_connections: std::env::var("DB_MAX_CONNECTIONS")
+                .ok()
+                .and_then(|v| v.parse().ok())
+                .unwrap_or(5),
+        })
+    }
+}