fix(engine): preserve real input targets across framework updates

[pathscale]

Native ps-qa could report false slider failures or false passes after scrolling. Revealing a named text node crashed in final_layout, a Solid delegated handler could be collected while its DOM node was still connected, and node-addressed activation bypassed the renderer's normal pointer sequence.

This release keeps connected DOM wrappers alive for their browser lifetime, routes semantic activation through the real UI event driver, and centers revealed controls in their scrollport and viewport so fixed chrome cannot cover the generated pointer point. ps-blitz is prepared as 0.4.9.

Local release evidence:

• cargo fmt --all -- --check
• cargo test -p ps-blitz-dom: 96/96
• fragment navigation: 6/6, preserving normal start alignment while agent reveal uses centered placement
• complete cargo test -p ps-blitz-script, including Solid delegated events, pointer capture drags, framework remounts, and detached-node reclamation
• coordinated js.software native suite with the matching protocol and host: 347/347 across 12 groups; all Slider and Color Picker pointer coordinates were inside the rendered viewport

The protocol and ps-qa side is in pathscale/ps-observability#20. The owner reviews this PR before any merge or release.