Add SendGrid access review driver

Implement a SendGrid access-review driver that fetches teammates
from the SendGrid API and maps them into AccountRecord values.

Register SendGrid as a connector provider, expose it through the
connector provider enum, and add a migration that extends the
connector_provider type with SENDGRID.

Cover the new driver with a VCR-backed fixture test and helper
tests for role and response-shape handling to keep parsing robust.

Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>

pkg/accessreview/drivers/sendgrid_test.go

@@ -0,0 +1,115 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package drivers
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.probo.inc/probo/pkg/coredata"
+)
+
+func TestSendGridDriver(t *testing.T) {
+	t.Parallel()
+
+	rec := newRecorder(t, "testdata/sendgrid", "SENDGRID_API_KEY")
+	client := newVCRClient(rec, bearerAuth(os.Getenv("SENDGRID_API_KEY")))
+	driver := NewSendGridDriver(client)
+
+	records, err := driver.ListAccounts(context.Background())
+	require.NoError(t, err)
+	require.Len(t, records, 3)
+
+	owner := records[0]
+	assert.Equal(t, "owner@example.com", owner.Email)
+	assert.Equal(t, "Olivia Owner", owner.FullName)
+	assert.Equal(t, "Owner", owner.Role)
+	assert.True(t, owner.IsAdmin)
+	assert.Equal(t, "owner-user", owner.ExternalID)
+	assert.Equal(t, coredata.AccessEntryAccountTypeUser, owner.AccountType)
+
+	admin := records[1]
+	assert.Equal(t, "admin@example.com", admin.Email)
+	assert.Equal(t, "Admin", admin.Role)
+	assert.True(t, admin.IsAdmin)
+	assert.Equal(t, "admin-user", admin.ExternalID)
+
+	teammate := records[2]
+	assert.Equal(t, "teammate@example.com", teammate.Email)
+	assert.Equal(t, "Teammate", teammate.Role)
+	assert.False(t, teammate.IsAdmin)
+	assert.Equal(t, "teammate-user", teammate.ExternalID)
+}
+
+func TestSendGridRole(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		userType string
+		isAdmin  bool
+		want     string
+	}{
+		{name: "owner", userType: "owner", isAdmin: true, want: "Owner"},
+		{name: "admin", userType: "admin", isAdmin: true, want: "Admin"},
+		{name: "teammate", userType: "teammate", isAdmin: false, want: "Teammate"},
+		{name: "empty admin", userType: "", isAdmin: true, want: "Admin"},
+		{name: "empty teammate", userType: "", isAdmin: false, want: "Teammate"},
+		{name: "unknown", userType: "custom-role", isAdmin: false, want: "custom-role"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			assert.Equal(t, tt.want, sendGridRole(tt.userType, tt.isAdmin))
+		})
+	}
+}
+
+func TestSendGridResponseItems(t *testing.T) {
+	t.Parallel()
+
+	t.Run("prefers result", func(t *testing.T) {
+		t.Parallel()
+
+		items := sendGridResponseItems(&sendGridTeammatesResponse{
+			Result: []sendGridTeammate{
+				{Email: "owner@example.com"},
+			},
+			Results: []sendGridTeammate{
+				{Email: "fallback@example.com"},
+			},
+		})
+
+		require.Len(t, items, 1)
+		assert.Equal(t, "owner@example.com", items[0].Email)
+	})
+
+	t.Run("falls back to results", func(t *testing.T) {
+		t.Parallel()
+
+		items := sendGridResponseItems(&sendGridTeammatesResponse{
+			Results: []sendGridTeammate{
+				{Email: "fallback@example.com"},
+			},
+		})
+
+		require.Len(t, items, 1)
+		assert.Equal(t, "fallback@example.com", items[0].Email)
+	})
+}