feat: add Autotask tags sync (tag groups, tags, ticket tag associations)

- Migration 057: autotask_tag_groups, autotask_tags, and junction tables
  (ticket_tags, company_tags, configuration_item_tags, contact_tags)
- Add TAG_GROUPS and TAGS to EntityType enum and dependency map
- Add mapTagGroup() and mapTag() entity mapper functions
- Add syncTagGroups(), syncTags(), syncTicketTagAssociations() methods
- Wire TicketTagAssociations bulk sync into full/incremental sync flow
- Add 'exist' operator to QueryFilter type
- No FK on ticket_id (tagged tickets may be outside 2yr sync window)

Synced: 26 tag groups, 7299 tags, 10141 ticket-tag associations

lib/auth.ts

@@ -73,6 +73,14 @@ export const auth = betterAuth({
     nextCookies(),
   ],
 
+  // Allow Microsoft OAuth to link to existing accounts created by admins
+  account: {
+    accountLinking: {
+      enabled: true,
+      trustedProviders: ["microsoft"],
+    },
+  },
+
   // User configuration
   user: {
     additionalFields: {