feat: expand companion platform, device controls, and memoir workflows

Add customer and operator login, BLE provisioning, device fleet controls, call memory, memoir generation, and refreshed family and maintenance portals. Include API contracts, migrations, firmware sources, tests, assets, and deployment documentation.

migrations/000070_sms_purpose.down.sql

@@ -0,0 +1,5 @@
+BEGIN;
+ALTER TABLE operator_sms_challenge DROP COLUMN purpose;
+ALTER TABLE customer_sms_challenge DROP COLUMN purpose;
+ALTER TABLE onboarding_sms_challenge DROP COLUMN purpose;
+COMMIT;