Move comms work to background goroutine

This is a sort of random checkpoint of work
 * add schema for tracking messages sent to DB
 * add terms of service and privacy policy for RCS compliance
 * standardize some things about background workers
 * update some missing stuff from generated DB code

db/dberrors/comms.email.bob.go

@@ -0,0 +1,17 @@
+// Code generated by BobGen psql v0.42.1. DO NOT EDIT.
+// This file is meant to be re-generated in place and/or deleted at any time.
+
+package dberrors
+
+var CommsEmailErrors = &commsEmailErrors{
+	ErrUniqueEmailPkey: &UniqueConstraintError{
+		schema:  "comms",
+		table:   "email",
+		columns: []string{"address"},
+		s:       "email_pkey",
+	},
+}
+
+type commsEmailErrors struct {
+	ErrUniqueEmailPkey *UniqueConstraintError
+}