feat(notifications+admin): marketing campaigns

- campaigns table (migration 19) + CRUD + send endpoint in notification-svc
- audience resolution reads cross-schema from identity.users (all / verified /
  with_plan); send dispatches via the SMS or Email channel and logs deliveries
- endpoints: GET/POST /v1/campaigns, POST /v1/campaigns/:id/send, DELETE
- gateway route /v1/campaigns/* → notification
- /admin/marketing: create campaign (channel, audience, template/subject/body),
  list with status + sent counts, send, delete

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/notification/internal/db/campaigns.go

@@ -0,0 +1,110 @@
+package db
+
+import (
+	"context"
+
+	"github.com/flatrender/notification-svc/internal/models"
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+)
+
+func (s *Store) ListCampaigns(ctx context.Context, tenantID uuid.UUID) ([]*models.Campaign, error) {
+	rows, err := s.pool.Query(ctx,
+		`SELECT id, tenant_id, name, channel, audience, subject, body_html, template_code,
+		        status, total_count, sent_count, failed_count, created_at, sent_at
+		 FROM notification.campaigns WHERE tenant_id = $1 ORDER BY created_at DESC`, tenantID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []*models.Campaign
+	for rows.Next() {
+		c := &models.Campaign{}
+		if err := rows.Scan(&c.ID, &c.TenantID, &c.Name, &c.Channel, &c.Audience, &c.Subject,
+			&c.BodyHTML, &c.TemplateCode, &c.Status, &c.TotalCount, &c.SentCount, &c.FailedCount,
+			&c.CreatedAt, &c.SentAt); err != nil {
+			return nil, err
+		}
+		out = append(out, c)
+	}
+	return out, rows.Err()
+}
+
+func (s *Store) GetCampaign(ctx context.Context, id, tenantID uuid.UUID) (*models.Campaign, error) {
+	c := &models.Campaign{}
+	err := s.pool.QueryRow(ctx,
+		`SELECT id, tenant_id, name, channel, audience, subject, body_html, template_code,
+		        status, total_count, sent_count, failed_count, created_at, sent_at
+		 FROM notification.campaigns WHERE id = $1 AND tenant_id = $2`, id, tenantID).
+		Scan(&c.ID, &c.TenantID, &c.Name, &c.Channel, &c.Audience, &c.Subject, &c.BodyHTML,
+			&c.TemplateCode, &c.Status, &c.TotalCount, &c.SentCount, &c.FailedCount, &c.CreatedAt, &c.SentAt)
+	if err == pgx.ErrNoRows {
+		return nil, nil
+	}
+	return c, err
+}
+
+func (s *Store) CreateCampaign(ctx context.Context, tenantID uuid.UUID, req models.CreateCampaignRequest) (*models.Campaign, error) {
+	audience := req.Audience
+	if audience == "" {
+		audience = "all"
+	}
+	var id uuid.UUID
+	err := s.pool.QueryRow(ctx,
+		`INSERT INTO notification.campaigns (tenant_id, name, channel, audience, subject, body_html, template_code)
+		 VALUES ($1,$2,$3,$4,$5,$6,$7) RETURNING id`,
+		tenantID, req.Name, req.Channel, audience, req.Subject, req.BodyHTML, req.TemplateCode).Scan(&id)
+	if err != nil {
+		return nil, err
+	}
+	return s.GetCampaign(ctx, id, tenantID)
+}
+
+func (s *Store) DeleteCampaign(ctx context.Context, id, tenantID uuid.UUID) error {
+	_, err := s.pool.Exec(ctx, `DELETE FROM notification.campaigns WHERE id=$1 AND tenant_id=$2`, id, tenantID)
+	return err
+}
+
+func (s *Store) UpdateCampaignResult(ctx context.Context, id uuid.UUID, status string, total, sent, failed int) error {
+	_, err := s.pool.Exec(ctx,
+		`UPDATE notification.campaigns SET status=$2, total_count=$3, sent_count=$4, failed_count=$5,
+		        sent_at = CASE WHEN $2 IN ('Sent','Failed') THEN NOW() ELSE sent_at END
+		 WHERE id=$1`, id, status, total, sent, failed)
+	return err
+}
+
+// ResolveAudience returns recipient contact strings (email or phone) for a campaign
+// segment, read cross-schema from identity.users (same database).
+func (s *Store) ResolveAudience(ctx context.Context, tenantID uuid.UUID, channel, audience string, limit int) ([]string, error) {
+	col := "email"
+	notNull := "email IS NOT NULL AND email <> ''"
+	if channel == "sms" {
+		col = "phone_number"
+		notNull = "phone_number IS NOT NULL AND phone_number <> ''"
+	}
+	where := "tenant_id = $1 AND deleted_at IS NULL AND ban_account = FALSE AND " + notNull
+	switch audience {
+	case "verified":
+		if channel == "sms" {
+			where += " AND phone_verified = TRUE"
+		} else {
+			where += " AND email_verified = TRUE"
+		}
+	case "with_plan":
+		where += " AND EXISTS (SELECT 1 FROM identity.user_plans up WHERE up.user_id = identity.users.id AND (up.expires_at IS NULL OR up.expires_at > NOW()))"
+	}
+	q := "SELECT " + col + " FROM identity.users WHERE " + where + " LIMIT $2"
+	rows, err := s.pool.Query(ctx, q, tenantID, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []string
+	for rows.Next() {
+		var v string
+		if err := rows.Scan(&v); err == nil && v != "" {
+			out = append(out, v)
+		}
+	}
+	return out, rows.Err()
+}