[plan] Connect Multiple Repositories to Project

_Automatically composed from the parent epic at dispatch time._

Split on the Architect's C1–C9 boundaries into 9 coder children across 4 phases (C1 → C2/C3/C7 → C4/C8/C9 → C5/C6). C9 depends on C8 so each wave has one migration. Tightened the done-checks with the §6 risk tests. No Required checks lines (mem-11178).