Add serverFileId to FileEntry, pass fileId in tool processor formData when
a file originates from the Files page, and set serverFileId on the loaded
entry so subsequent tool runs create new file versions instead of duplicates.
After upload: dropzone replaced by image viewer with zoom controls.
After processing: review panel shows result preview, file info, download,
undo button, and suggested next tools for chaining.
Draggable split-view slider with clip-path reveals original vs processed
image. Shows file size badges with savings percentage. Supports pointer
events for both mouse and touch. Integrated into tool-page to replace
dropzone after processing completes. Updated file-store with
originalBlobUrl for comparison. Enhanced dropzone with multi-file count
badge and file list display.
Adds Zustand file store, useToolProcessor hook for upload/process/download
flow, and 7 settings components: resize (with social media presets), crop
(with aspect ratio presets), rotate/flip, convert, compress (quality +
target size modes), strip-metadata, and color adjustments (brightness,
contrast, saturation, channels, effects). Updates tool-page to render the
appropriate settings panel based on toolId.