Adds an admin-only "Numeros compartilhados entre leads" section to the
settings modal, wired to the Task 4 shared-numbers routes: lists
detected groups, lets an admin liberar (with an inline motivo input)
or bloquear de novo. Updates the two frontend VM-based test files'
default API mocks to answer GET /api/outreach/shared-numbers so
existing settings-modal tests keep passing, and adds a new
interaction test covering the liberar round trip.
Tracks the app that was already in place (capture, treatment, outreach,
WhatsApp integration, server, frontend, tests, docs) so future feature
work can branch and use isolated worktrees.