Adds a PROJECT_TEAM recipient type to the message router (resolver
returns team members + project lead) and an "Email Team" button on
the admin project detail page that opens a self-contained dialog
matching the look of /admin/messages: subject, body (pre-filled
with "Hello [Project Title] team,\n\n"), live HTML preview iframe,
"Send test to me" + "Send to N" actions.
The composer reuses the existing message.previewEmail and
message.send tRPC procedures end-to-end — no parallel email
infrastructure introduced.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>