Named component ref diagnostics

Point to the authored ref

Four archived Realtime first builds used non-null refs in named Feed components and received only a generic DOM-ref error. Kudzu now diagnoses an unsupported unattached ref at its source line, after proven effect-private refs have normalized.

Keep established boundaries

JSX-attached keyed-row and setter-child refs retain their more-specific diagnostics. The supported R8 WebSocket route still passes browser acceptance and emits eleven byte-identical files, including a JavaScript-free static sibling.

Account for cost honestly

This diagnostic correction has not been measured for model-token savings. The R22 independent cost confirmation retains four unknown timeout tails; the R8 success/cost gate and 1.0 remain blocked. Generator 0.1.158 is unchanged.