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.go

@@ -0,0 +1,165 @@
+// 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"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"go.probo.inc/probo/pkg/coredata"
+)
+
+type SendGridDriver struct {
+	httpClient *http.Client
+}
+
+var _ Driver = (*SendGridDriver)(nil)
+
+type sendGridTeammate struct {
+	Username  string `json:"username"`
+	Email     string `json:"email"`
+	FirstName string `json:"first_name"`
+	LastName  string `json:"last_name"`
+	UserType  string `json:"user_type"`
+	IsAdmin   bool   `json:"is_admin"`
+}
+
+type sendGridTeammatesResponse struct {
+	Result  []sendGridTeammate `json:"result"`
+	Results []sendGridTeammate `json:"results"`
+}
+
+const (
+	sendGridTeammatesEndpoint  = "https://api.sendgrid.com/v3/teammates"
+	sendGridTeammatesPageLimit = 500
+)
+
+func NewSendGridDriver(httpClient *http.Client) *SendGridDriver {
+	return &SendGridDriver{
+		httpClient: httpClient,
+	}
+}
+
+func (d *SendGridDriver) ListAccounts(ctx context.Context) ([]AccountRecord, error) {
+	var (
+		records []AccountRecord
+		offset  int
+	)
+
+	for range maxPaginationPages {
+		resp, err := d.fetchTeammates(ctx, offset)
+		if err != nil {
+			return nil, err
+		}
+
+		teammates := sendGridResponseItems(resp)
+		for _, teammate := range teammates {
+			if teammate.Email == "" {
+				continue
+			}
+
+			records = append(records, AccountRecord{
+				Email:       teammate.Email,
+				FullName:    sendGridFullName(teammate.FirstName, teammate.LastName),
+				Role:        sendGridRole(teammate.UserType, teammate.IsAdmin),
+				IsAdmin:     teammate.IsAdmin,
+				ExternalID:  strings.TrimSpace(teammate.Username),
+				MFAStatus:   coredata.MFAStatusUnknown,
+				AuthMethod:  coredata.AccessEntryAuthMethodUnknown,
+				AccountType: coredata.AccessEntryAccountTypeUser,
+			})
+		}
+
+		if len(teammates) < sendGridTeammatesPageLimit {
+			return records, nil
+		}
+
+		offset += len(teammates)
+	}
+
+	return nil, fmt.Errorf("cannot list all sendgrid teammates: %w", ErrPaginationLimitReached)
+}
+
+func (d *SendGridDriver) fetchTeammates(
+	ctx context.Context,
+	offset int,
+) (*sendGridTeammatesResponse, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, sendGridTeammatesEndpoint, nil)
+	if err != nil {
+		return nil, fmt.Errorf("cannot create sendgrid teammates request: %w", err)
+	}
+
+	q := req.URL.Query()
+	q.Set("limit", strconv.Itoa(sendGridTeammatesPageLimit))
+	q.Set("offset", strconv.Itoa(offset))
+	req.URL.RawQuery = q.Encode()
+
+	req.Header.Set("Accept", "application/json")
+
+	httpResp, err := d.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("cannot execute sendgrid teammates request: %w", err)
+	}
+
+	defer func() {
+		_ = httpResp.Body.Close()
+	}()
+
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		return nil, fmt.Errorf("cannot fetch sendgrid teammates: unexpected status %d", httpResp.StatusCode)
+	}
+
+	var resp sendGridTeammatesResponse
+	if err := json.NewDecoder(httpResp.Body).Decode(&resp); err != nil {
+		return nil, fmt.Errorf("cannot decode sendgrid teammates response: %w", err)
+	}
+
+	return &resp, nil
+}
+
+func sendGridResponseItems(resp *sendGridTeammatesResponse) []sendGridTeammate {
+	if len(resp.Result) > 0 {
+		return resp.Result
+	}
+
+	return resp.Results
+}
+
+func sendGridFullName(firstName, lastName string) string {
+	return strings.TrimSpace(strings.Join([]string{firstName, lastName}, " "))
+}
+
+func sendGridRole(userType string, isAdmin bool) string {
+	switch userType {
+	case "owner":
+		return "Owner"
+	case "admin":
+		return "Admin"
+	case "teammate":
+		return "Teammate"
+	case "":
+		if isAdmin {
+			return "Admin"
+		}
+
+		return "Teammate"
+	default:
+		return userType
+	}
+}