fix: disable incremental sync for Companies and Resources

Companies and Resources entities in Autotask API do not support
date-based filtering for incremental syncs. When attempting incremental
sync, Autotask returns errors:
- Companies: 'Unable to find lastTrackedModificationDateTime'
- Resources: 'Unable to find lastModifiedDate'

Solution:
- Skip incremental sync for these entities
- Always perform full sync for Companies and Resources
- Log informational message when falling back to full sync
- Other entities continue to support incremental sync normally

This prevents sync failures while maintaining data freshness for
Companies and Resources through full syncs.

lib/services/entity-sync.ts

@@ -85,7 +85,10 @@ export class EntitySyncService {
       let params: any = {};
 
       // For incremental sync, filter by last sync time
-      if (isIncremental) {
+      // Note: Companies and Resources don't support date-based filtering in Autotask API
+      const supportsIncremental = entity !== EntityType.COMPANIES && entity !== EntityType.RESOURCES;
+      
+      if (isIncremental && supportsIncremental) {
         try {
           const lastSyncTime = await getLastSyncTime(entity);
           if (lastSyncTime) {
@@ -99,6 +102,8 @@ export class EntitySyncService {
           entityLogger.error('Failed to get last sync time', {}, err);
           throw new Error(`Failed to determine sync time: ${err.message}`);
         }
+      } else if (isIncremental && !supportsIncremental) {
+        entityLogger.info(`${entity} does not support incremental sync, performing full sync instead`);
       } else {
         // For full sync, build filters
         const filters: Array<{ field: string; op: string; value: any }> = [];