Add the Marble and Highlighter templates, completing the 13 Canva templates

Marble uses a flat-to-gradient band in place of the marble photo and bundles Lustria (OFL).
Both logo slots are opt-in. Quirk 13 documents a fontkit glyph-cache issue that the
tests work around with warm-up renders; the engine fix follows separately.

src/pdf/templates/harness.sweep.ts

@@ -4,7 +4,7 @@ import { checkRendered } from "./harness.check";
 import { TEMPLATES } from "./registry";
 
 /** The standalone templates sweep in a file of their own, so vitest runs the two sweeps in parallel and the suite's wall time stays put. */
-export const STANDALONE_SWEEP = ["monolith", "cobalt-stripe"];
+export const STANDALONE_SWEEP = ["monolith", "cobalt-stripe", "marble", "highlighter"];
 
 /** 1..45 generated rows on A4 and Letter for the templates `pick` selects, each render through the harness checks. */
 export function describeSweep(pick: (id: string) => boolean): void {