`kcode-kweb-context-node` owns the typed node representation shared by Kweb
context projection consumers. It validates legacy Kweb JSON, preserves ordered
fixed and recent connection summaries, converts stored nodes into mutable
drafts, and renders the common full-node body.
The crate does not read Kweb, open Session History, choose which nodes are full,
or manage summary-box permanence. Those policies remain in
`kcode-kweb-context`.