Add Zeyu Zhang as a speaker for session iot-1213290

[SpriCoder]

What changed

• added Zeyu Zhang to the presenters front matter for session iot-1213290
• added Zeyu Zhang speaker details to both the English and Chinese session pages

Why

• Because the original speaker Hongyin Zhang was away on a business trip, another speaker was needed to give the presentation on-site. So the session needs one more speaker listed on the site

Validation

• compared the two edited Markdown files against upstream master
• confirmed the diff is limited to the requested speaker additions
• independent maintainer-style review reported READY FOR PR
• local Hugo build was intentionally skipped per requester instruction

[Alchuang22-dev]

LGTM!