Add Neon access review driver support

Register Neon as a connector provider and add a new access review
driver that fetches organization members from the Neon API with
cursor-based pagination.

Neon's OAuth is partner-gated, so the connector is API-key only
(Bearer, the default scheme). A personal or organization API key can
belong to several organizations; the operator supplies the ID of the
one to review. The members endpoint exposes per-user MFA state
(has_mfa) and deactivation, which map to the access entry MFA status
and active flag; the stable account UUID (user_id) is used as the
external ID over the membership ID.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/accessreview/drivers/neon.go

@@ -0,0 +1,205 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.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"
+	"net/url"
+	"strings"
+
+	"go.probo.inc/probo/pkg/coredata"
+)
+
+const (
+	neonAPIBaseURL = "https://console.neon.tech/api/v2"
+
+	// neonMembersPageLimit is the largest page size the Neon
+	// list-members endpoint documents (limit: 1..500).
+	neonMembersPageLimit = "500"
+)
+
+type NeonDriver struct {
+	httpClient     *http.Client
+	organizationID string
+}
+
+var _ Driver = (*NeonDriver)(nil)
+
+type neonMembersResponse struct {
+	Members    []neonOrgMember `json:"members"`
+	Pagination struct {
+		Next string `json:"next"`
+	} `json:"pagination"`
+}
+
+type neonOrgMember struct {
+	Member struct {
+		ID       string `json:"id"`
+		UserID   string `json:"user_id"`
+		Role     string `json:"role"`
+		JoinedAt string `json:"joined_at"`
+	} `json:"member"`
+	User struct {
+		Email         string `json:"email"`
+		HasMFA        *bool  `json:"has_mfa"`
+		DeactivatedAt string `json:"deactivated_at"`
+	} `json:"user"`
+}
+
+func NewNeonDriver(httpClient *http.Client, organizationID string) *NeonDriver {
+	return &NeonDriver{
+		httpClient:     httpClient,
+		organizationID: organizationID,
+	}
+}
+
+func (d *NeonDriver) ListAccounts(ctx context.Context) ([]AccountRecord, error) {
+	var (
+		records []AccountRecord
+		cursor  string
+	)
+
+	for range maxPaginationPages {
+		resp, err := d.queryMembers(ctx, cursor)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, m := range resp.Members {
+			if m.User.Email == "" {
+				continue
+			}
+
+			records = append(records, AccountRecord{
+				Email: m.User.Email,
+				// The members endpoint exposes no display name;
+				// fall back to the email.
+				FullName: m.User.Email,
+				Role:     neonRole(m.Member.Role),
+				// deactivated_at is absent for active accounts.
+				Active:      new(m.User.DeactivatedAt == ""),
+				IsAdmin:     neonIsAdmin(m.Member.Role),
+				MFAStatus:   neonMFAStatus(m.User.HasMFA),
+				AuthMethod:  coredata.AccessEntryAuthMethodUnknown,
+				AccountType: coredata.AccessEntryAccountTypeUser,
+				ExternalID:  neonExternalID(m),
+				CreatedAt:   parseRFC3339Ptr(m.Member.JoinedAt),
+			})
+		}
+
+		if resp.Pagination.Next == "" {
+			return records, nil
+		}
+
+		cursor = resp.Pagination.Next
+	}
+
+	return nil, fmt.Errorf("cannot list all neon accounts: %w", ErrPaginationLimitReached)
+}
+
+func (d *NeonDriver) queryMembers(ctx context.Context, cursor string) (*neonMembersResponse, error) {
+	endpoint, err := url.JoinPath(
+		neonAPIBaseURL,
+		"organizations",
+		url.PathEscape(d.organizationID),
+		"members",
+	)
+	if err != nil {
+		return nil, fmt.Errorf("cannot build neon members URL: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+	if err != nil {
+		return nil, fmt.Errorf("cannot create neon members request: %w", err)
+	}
+
+	req.Header.Set("Accept", "application/json")
+
+	q := req.URL.Query()
+	q.Set("limit", neonMembersPageLimit)
+
+	if cursor != "" {
+		q.Set("cursor", cursor)
+	}
+
+	req.URL.RawQuery = q.Encode()
+
+	httpResp, err := d.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("cannot execute neon members request: %w", err)
+	}
+
+	defer func() {
+		_ = httpResp.Body.Close()
+	}()
+
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		return nil, fmt.Errorf("cannot fetch neon members: unexpected status %d", httpResp.StatusCode)
+	}
+
+	var resp neonMembersResponse
+	if err := json.NewDecoder(httpResp.Body).Decode(&resp); err != nil {
+		return nil, fmt.Errorf("cannot decode neon members response: %w", err)
+	}
+
+	return &resp, nil
+}
+
+// neonRole maps Neon's lowercase member roles to their display form,
+// passing unknown values through unchanged.
+func neonRole(role string) string {
+	switch strings.ToLower(role) {
+	case "admin":
+		return "Admin"
+	case "member":
+		return "Member"
+	case "editor":
+		return "Editor"
+	case "viewer":
+		return "Viewer"
+	case "collaborator":
+		return "Collaborator"
+	default:
+		return role
+	}
+}
+
+func neonIsAdmin(role string) bool {
+	return strings.EqualFold(role, "admin")
+}
+
+func neonMFAStatus(hasMFA *bool) coredata.MFAStatus {
+	switch {
+	case hasMFA == nil:
+		return coredata.MFAStatusUnknown
+	case *hasMFA:
+		return coredata.MFAStatusEnabled
+	default:
+		return coredata.MFAStatusDisabled
+	}
+}
+
+// neonExternalID prefers the stable Neon account UUID over the
+// membership ID.
+func neonExternalID(m neonOrgMember) string {
+	if m.Member.UserID != "" {
+		return m.Member.UserID
+	}
+
+	return m.Member.ID
+}