Add exact-identity target storage adapter

crates/remora-target/tests/redaction.rs

@@ -0,0 +1,19 @@
+use remora_target::TargetStoreConfig;
+
+#[test]
+fn target_store_config_debug_redacts_secret() {
+    let config = TargetStoreConfig::new_exclusive(
+        "garage",
+        "http://garage:3900",
+        "remora-lane-001",
+        "garage",
+        "synthetic-access-key",
+        "synthetic-secret-key-must-not-leak",
+        "",
+    )
+    .expect("config");
+    let debug = format!("{config:?}");
+    assert!(!debug.contains("synthetic-secret-key-must-not-leak"));
+    assert!(debug.contains("REDACTED"));
+    assert!(debug.contains("synthetic-access-key"));
+}