Move the kanban full-page shell into a checked .heml unit so page assembly uses slhx render/SafeHtml composition instead of hand-built trusted HTML strings.
req: html_safety/001
req: html_safety/002
req: component/003
Move the kanban SSE presence fragment from Rust raw HTML formatting into a hemplate partial/view and cover the rendered structure with scraper.
req: html_safety/002
req: view/001
req: test/005