The chat composer inserted comms_messages straight from the browser with
CLIENT-SUPPLIED user_id/display_name/handle/space_id — a member could forge
another person's name/handle. Add a sendMessage server action that derives
identity from the session, verifies the channel belongs to the caller's space,
validates content, and logs the send. The optimistic insert + realtime
subscription are preserved, so latency is unchanged. loadMessages stays on the
browser client (the realtime subscription needs it) with a comment noting it.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
1141-line lib/validations.ts → lib/validations/<feature>.ts + primitives.ts +
an index.ts barrel. '@/lib/validations' now resolves to the barrel, so all 40
importers are untouched. Every one of the 143 exports is preserved verbatim
(verified by symbol-diff); schemas moved unchanged. tsc 0, 635 tests green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>