refactor(db): replace sqlc with handwritten pgx repos

- Finish Paddle-to-Stripe billing migration; drop paddle/stripe libs
- Renumber migrations; add 00012 memberships+manage_token,
  00013 location_type_capacity
- Add tests: admin, auth, bookings customer service
- Remove graphify-out artifacts and stale env files

Authored By: TDvorak <[email protected]>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/internal/db/email_templates.go

@@ -0,0 +1,55 @@
+package db
+
+import (
+	"context"
+)
+
+func (r *PGRepository) ListEmailTemplates(ctx context.Context, tenantID string) ([]EmailTemplateRecord, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, tenant_id, type, subject, body_html, body_text, is_enabled, updated_at
+		FROM email_templates
+		WHERE tenant_id = $1
+		ORDER BY type
+	`, tenantID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var records []EmailTemplateRecord
+	for rows.Next() {
+		var rec EmailTemplateRecord
+		if err := rows.Scan(&rec.ID, &rec.TenantID, &rec.Type, &rec.Subject, &rec.BodyHTML, &rec.BodyText, &rec.IsEnabled, &rec.UpdatedAt); err != nil {
+			return nil, err
+		}
+		records = append(records, rec)
+	}
+	return records, rows.Err()
+}
+
+func (r *PGRepository) GetEmailTemplate(ctx context.Context, tenantID string, templateType string) (EmailTemplateRecord, error) {
+	var rec EmailTemplateRecord
+	err := r.pool.QueryRow(ctx, `
+		SELECT id, tenant_id, type, subject, body_html, body_text, is_enabled, updated_at
+		FROM email_templates
+		WHERE tenant_id = $1 AND type = $2
+	`, tenantID, templateType).Scan(&rec.ID, &rec.TenantID, &rec.Type, &rec.Subject, &rec.BodyHTML, &rec.BodyText, &rec.IsEnabled, &rec.UpdatedAt)
+	return rec, err
+}
+
+func (r *PGRepository) UpsertEmailTemplate(ctx context.Context, params EmailTemplateRecord) (EmailTemplateRecord, error) {
+	var rec EmailTemplateRecord
+	err := r.pool.QueryRow(ctx, `
+		INSERT INTO email_templates (tenant_id, type, subject, body_html, body_text, is_enabled)
+		VALUES ($1, $2, $3, $4, $5, $6)
+		ON CONFLICT (tenant_id, type) DO UPDATE SET
+			subject = EXCLUDED.subject,
+			body_html = EXCLUDED.body_html,
+			body_text = EXCLUDED.body_text,
+			is_enabled = EXCLUDED.is_enabled,
+			updated_at = now()
+		RETURNING id, tenant_id, type, subject, body_html, body_text, is_enabled, updated_at
+	`, params.TenantID, params.Type, params.Subject, params.BodyHTML, params.BodyText, params.IsEnabled).Scan(
+		&rec.ID, &rec.TenantID, &rec.Type, &rec.Subject, &rec.BodyHTML, &rec.BodyText, &rec.IsEnabled, &rec.UpdatedAt)
+	return rec, err
+}