PR #182 review (post-fix pass) surfaced two latent correctness risks in the
new MessageItem memo: the per-message signature tracks only [type, text length,
state, error/output presence] + metadata, so a part kind whose VISIBLE content
can change WITHOUT changing those fields would silently freeze a stale row.
Neither is reachable with the current toolset (tool output is set once;
streaming is append-only with a fixed id), so the correct fix is to harden the
documented invariant rather than hash output content on every delta (getPage
returns full page content — hashing it per-delta would tax the hot path this
PR optimizes).
Add a WARNING in messageSignature naming the two future triggers (a tool that
streams `preliminary` output; a client-side regenerate/edit that mutates a
finalized row in place) and the required action (extend the signature).
No behavior change (comment only). vitest src/features/ai-chat 189/189 pass,
tsc clean for the touched files.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>