feat: Mimecast multi-tenant held mail viewer

- migration 062: mimecast_tenants table (company_id, client_id/secret, account_code)
- Seed Wulf (CUSA13A95) + Seubert (CUSA96A181) tenants
- MimecastClient.getHeldMessages(): full pagination via meta.pagination.next cursor
  (API always returns 10/page regardless of pageSize param, totalCount in meta)
- getMimecastClientForTenant() factory for per-tenant instantiation
- GET /api/mimecast/held?tenantId=&recipient= — fetches all tenants in parallel,
  merges + sorts by date, returns per-tenant counts + combined messages[]
- Held Mail tab on /admin/sync/mimecast (on-demand load, recipient filter,
  tenant badges, policy filter dropdown, DMARC/impersonation highlighted red)

app/api/sync/classifications/route.ts

@@ -6,18 +6,20 @@ export async function POST(request: NextRequest) {
   try {
     console.log('Starting classification icons sync...');
 
-    // Fetch classification icons from Autotask API
+    // Fetch classification picklist from Companies field info
     const autotaskClient = getAutotaskClient();
-    const classifications = await autotaskClient.getClassificationIcons();
-    
-    if (!classifications || classifications.length === 0) {
+    const fields = await autotaskClient.getFieldInfo('Companies');
+    const classificationField = fields.find((f: any) => f.name === 'classification');
+
+    if (!classificationField || !classificationField.picklistValues?.length) {
       return NextResponse.json(
-        { error: 'No classifications found in Autotask' },
+        { error: 'No classification picklist found in Companies field info' },
         { status: 404 }
       );
     }
 
-    console.log(`Fetched ${classifications.length} classification icons from Autotask`);
+    const classifications = classificationField.picklistValues;
+    console.log(`Fetched ${classifications.length} classification values from Autotask`);
 
     let inserted = 0;
     let updated = 0;
@@ -26,16 +28,16 @@ export async function POST(request: NextRequest) {
     for (const classification of classifications) {
       const result = await postgresClient.query(
         `INSERT INTO company_classifications (
-          classification_id, 
-          name, 
-          description, 
+          classification_id,
+          name,
+          description,
           is_active,
           is_system,
           updated_at,
           synced_at
         ) VALUES ($1, $2, $3, $4, $5, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
-        ON CONFLICT (classification_id) 
-        DO UPDATE SET 
+        ON CONFLICT (classification_id)
+        DO UPDATE SET
           name = EXCLUDED.name,
           description = EXCLUDED.description,
           is_active = EXCLUDED.is_active,
@@ -44,9 +46,9 @@ export async function POST(request: NextRequest) {
           synced_at = CURRENT_TIMESTAMP
         RETURNING (xmax = 0) AS inserted`,
         [
-          classification.id,
-          classification.name,
-          classification.description || null,
+          parseInt(String(classification.value)),
+          classification.label,
+          null,
           classification.isActive !== false,
           classification.isSystem || false
         ]
@@ -66,7 +68,7 @@ export async function POST(request: NextRequest) {
       total: classifications.length,
       inserted,
       updated,
-      message: `Synced ${classifications.length} classification icons`
+      message: `Synced ${classifications.length} classifications from Companies field info`
     });
 
   } catch (error) {