TeamMemberChip used MAX_NESTING_DEPTH to cap recursive sub-agent
rendering at depth 3, but the constant was never declared — causing
a TypeScript build error ('Cannot find name MAX_NESTING_DEPTH') that
blocked Canvas CI on PR #1989.
Add the constant above EmbeddedTeam with a doc comment explaining its
purpose (guards against circular parentId cycles + readability cap).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>