feat: config crate with legacy env names

crates/config/src/auth_config.rs

@@ -0,0 +1,38 @@
+use std::fmt;
+
+use serde::Deserialize;
+
+use crate::lenient;
+
+#[derive(Clone, Deserialize)]
+#[serde(default)]
+pub struct AuthConfig {
+    pub jwt_secret: Option<String>,
+    #[serde(deserialize_with = "lenient::number")]
+    pub jwt_ttl_seconds: u64,
+    #[serde(deserialize_with = "lenient::number")]
+    pub refresh_ttl_seconds: u64,
+}
+
+impl Default for AuthConfig {
+    fn default() -> Self {
+        Self {
+            jwt_secret: None,
+            jwt_ttl_seconds: 900,
+            refresh_ttl_seconds: 2_592_000,
+        }
+    }
+}
+
+impl fmt::Debug for AuthConfig {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("AuthConfig")
+            .field(
+                "jwt_secret",
+                &self.jwt_secret.as_ref().map(|_| "<redacted>"),
+            )
+            .field("jwt_ttl_seconds", &self.jwt_ttl_seconds)
+            .field("refresh_ttl_seconds", &self.refresh_ttl_seconds)
+            .finish()
+    }
+}