feat: agency control panel for per-client connections

Matrix view of Meta/Google/Drive/Clientify, follow/archive clients,
and per-channel ON/OFF with account IDs in the client hub.

Co-authored-by: Cursor <cursoragent@cursor.com>

sql/agency_control.sql

@@ -0,0 +1,16 @@
+-- Agency control: follow/archive clients + enable/disable channels
+-- Idempotent.
+
+alter table public.tenants
+  add column if not exists agency_followed boolean not null default true;
+
+alter table public.tenants
+  add column if not exists agency_notes text;
+
+alter table public.integrations
+  add column if not exists enabled boolean not null default true;
+
+comment on column public.tenants.agency_followed is
+  'Agency portfolio: false = archived / not actively managed in Centro de Mando';
+comment on column public.integrations.enabled is
+  'Agency wants this channel for the client (false = deliberately off)';