Devlog 31: Template Canvas Architecture & Reference Refactoring

Independent Canvas Architecture

• Replaced direct DOM manipulation of live dashboard elements with a dedicated, off-screen template canvas (.export-canvas).
• Cloned active .progress-card elements into an isolated container (.export-cards-holder), ensuring the on-screen UI remains completely untouched and non-flickering during image generation.
• Moved aspect ratio, high-resolution dimensions (600x600), padding, and font-scaling rules directly into CSS for clean separation of concerns.

Error Fixes & Cleanup

• Fixed ReferenceError caused by leftover references to targetContainer and stampEl inside initExportImageFeature.
• Updated html2canvas target from main dashboard container to the temporary canvasEl.
• Streamlined fallback DOM cleanup logic inside the try...catch block to guarantee off-screen elements are properly garbage collected.