feat(bootstrap): composition root with Config + factory.rs

crates/bootstrap/src/config.rs

@@ -0,0 +1,36 @@
+/// All configuration read from environment variables at startup.
+pub struct Config {
+    pub database_url: String,
+    pub jwt_secret: String,
+    pub base_url: String,
+    pub nats_url: Option<String>,
+    pub port: u16,
+    pub allow_registration: bool,
+    /// true when RUST_ENV != "production" — enables AP debug mode
+    pub debug: bool,
+}
+
+impl Config {
+    pub fn from_env() -> Self {
+        dotenvy::dotenv().ok();
+        Self {
+            database_url: std::env::var("DATABASE_URL")
+                .expect("DATABASE_URL is required"),
+            jwt_secret: std::env::var("JWT_SECRET")
+                .expect("JWT_SECRET is required"),
+            base_url: std::env::var("BASE_URL")
+                .unwrap_or_else(|_| "http://localhost:3000".into()),
+            nats_url: std::env::var("NATS_URL").ok(),
+            port: std::env::var("PORT")
+                .ok()
+                .and_then(|p| p.parse().ok())
+                .unwrap_or(3000),
+            allow_registration: std::env::var("ALLOW_REGISTRATION")
+                .map(|v| v == "true")
+                .unwrap_or(true),
+            debug: std::env::var("RUST_ENV")
+                .map(|v| v != "production")
+                .unwrap_or(true),
+        }
+    }
+}