GeezerVison

• I have read the Contribution guide
• This PR references an issue (except for typos, broken links, or other minor problems)

Description(required)

solidjs/solid#4773 asks when to reach for createDeferred, and suggests it is the same as reading every consumer through latest. It is not: latest changes what one reader shows while the update stays held for every other reader, whereas a deferred memo is not part of the update at all, so nothing waits for it.

• Async reactivity concept page: a new "Let a panel lag: createDeferred" section after the latest one, using the page's own dashboard (the ten-second audit panel). It contrasts reader-side latest with source-side createDeferred, says when to use each, and notes that a deferred memo lags but never leads (its first load still suspends; a refetch that reads a held value lands with that hold). The update decision table gains a fourth row pointing to it.
• createDeferred reference: a Caveats section with the same distinction. It is added to ENTRY_CAVEATS in scripts/extract-solid-ref.mjs and written into the generated page by hand. A full sync:ref run against current next stops on an unrelated new export (verdict) that has no disposition yet.

The semantics follow Solid's ruling for deferred sources (D-40: a deferred source lags its readers and never leads them).

Related issues & labels

• Closes Improve createDeferred v2 documentation: when should it be used over createMemo? solid#4773
• Suggested label(s) (optional): documentation

Generated by Claude Code