UTF16 Surrogate Slice Tests Motion Study

Create a 12-second reference-led video for coding using [string slicing interface], [Unicode fixtures] and [indexing contract]. Core visible action: one supplementary character occupies two code-unit boxes while a boundary marker shows a potentially invalid split. The intended task is to design tests for slicing at UTF-16 surrogate boundaries; distinguish code units, code points and grapheme clusters and state whether broken surrogate output is rejected or preserved by contract. Use three shots: establish at 0–3 seconds, demonstrate at 3–9 seconds, hold the result at 9–12 seconds. Make the result understandable without sound. Use one consistent set of props; do not add unsupported labels, quantities or transformations.

Confirm required reference images and timing inputs are present before generating. Keep objects, identities, spatial relationships and light direction consistent. Render the clip when video generation is supported; otherwise supply a timed shot list, reference checklist and generation-ready prompt, labeled as a production plan. Do not claim rendered output without an actual file. Check the opening, transition and final frame against the stated counts and geometry.