fix(vfs): Z-04 — implement webdav quota report

tests/mount_security_test.rs

@@ -242,4 +242,73 @@ fn test_z01_decoy_password_zeroize_memory() {
     drop(ephemeral);
 }
 
+#[tokio::test]
+async fn test_z04_webdav_quota_report() {
+    use dav_server::fs::DavFileSystem;
+    use sanctum::vfs::SanctumFs;
+
+    let temp_dir = std::env::temp_dir();
+    let container_path: PathBuf =
+        temp_dir.join(format!("test_z04_quota_{}.sanctum", std::process::id()));
+    if container_path.exists() {
+        let _ = std::fs::remove_file(&container_path);
+    }
+
+    let salt = generate_salt();
+    let kdf_params = KdfParams {
+        memory_cost: MIN_MEMORY_COST_KIB,
+        time_cost: MIN_TIME_COST,
+        parallelism: 1,
+    };
+    let kek = derive_kek("TestPassZ04!", &salt, &kdf_params).unwrap();
+    let dek = generate_dek();
+    let (wrapped_dek, nonce, tag) = wrap_dek(&kek, &dek).unwrap();
+
+    let db = Database::open(&container_path).unwrap();
+    db.init_schema(&salt, &kdf_params, &wrapped_dek, &nonce, &tag)
+        .unwrap();
+
+    // Erstelle einen Testknoten mit Chunks
+    let node = db.create_node(1, "payload.bin", false).unwrap();
+    let dummy_chunk = vec![0xAAu8; 1024 * 1024]; // 1 MiB
+    db.write_chunk_and_update_size(
+        node.id,
+        0,
+        0,
+        &[0u8; 12],
+        &[0u8; 16],
+        &dummy_chunk,
+        1024 * 1024,
+        123456,
+    )
+    .unwrap();
+
+    let fs = SanctumFs::new(db.clone(), dek, sanctum::crypto::FORMAT_VERSION);
+
+    // Rufe WebDAV get_quota ab
+    let (used, total_opt) = fs.get_quota().await.unwrap();
+
+    assert!(
+        used > 0,
+        "Z-04: Verwendeter Speicherplatz muss > 0 sein (gemeldet: {} Bytes)",
+        used
+    );
+    assert!(
+        total_opt.is_some(),
+        "Z-04: Gesamtkapazität muss gemeldet werden"
+    );
+    let total = total_opt.unwrap();
+    assert!(
+        total >= used,
+        "Z-04: Gesamtkapazität ({}) muss mindestens dem belegten Speicher ({}) entsprechen",
+        total,
+        used
+    );
+
+    drop(fs);
+    drop(db);
+    let _ = std::fs::remove_file(&container_path);
+}
+
+