feat(one-time-downloads): add expiry and retry configuration

Introduce new environment variables to control the behavior of one-time download boxes:
- `WARPBOX_ONE_TIME_DOWNLOAD_EXPIRY_SECONDS`: Sets the lifetime of a one-time box after uploads are complete.
- `WARPBOX_ONE_TIME_DOWNLOAD_RETRY_ON_FAILURE`: Determines whether a box remains available if the ZIP creation or transfer fails.

To support these settings, the ZIP delivery process was refactored to use a temporary file. This ensures that a one-time box is only marked as consumed after the file has been successfully transferred to the client, preventing data loss on network interruptions.

Additionally, added a `DecorateFiles` helper in the box store to reduce code duplication.

Dockerfile

@@ -47,6 +47,8 @@ ENV WARPBOX_DATA_DIR=/app/data \
     WARPBOX_API_ENABLED=true \
     WARPBOX_ZIP_DOWNLOADS_ENABLED=true \
     WARPBOX_ONE_TIME_DOWNLOADS_ENABLED=true \
+    WARPBOX_ONE_TIME_DOWNLOAD_EXPIRY_SECONDS=604800 \
+    WARPBOX_ONE_TIME_DOWNLOAD_RETRY_ON_FAILURE=false \
     WARPBOX_ADMIN_ENABLED=true \
     WARPBOX_GLOBAL_MAX_FILE_SIZE_MB=2048 \
     WARPBOX_GLOBAL_MAX_BOX_SIZE_MB=4096 \
@@ -60,4 +62,4 @@ EXPOSE 8080
 
 VOLUME ["/app/data"]
 
-CMD ["./warpbox", "run", "--addr", ":8080"]
+CMD ["./warpbox", "run", "--addr", ":8080"]