Complete editable fields whitelists for all remaining AE objects

- Created .editable_fields.ts files for Journals, Events, and Sponsorships modules
- Standardized the whitelist pattern across the entire codebase
- Updated TODO.md and GEMINI.md with recent accomplishments and learnings

src/lib/ae_events/ae_events__exhibit.editable_fields.ts

@@ -0,0 +1,32 @@
+export const editable_fields__event_exhibit = [
+    'code',
+    'name',
+    'description',
+    'staff_passcode',
+    'data_json',
+    'leads_api_access',
+    'leads_custom_questions_json',
+    'leads_device_sm_qty',
+    'leads_device_lg_qty',
+    'license_max',
+    'license_li_json',
+    'cfg_json',
+    'enable',
+    'hide',
+    'priority',
+    'sort',
+    'group',
+    'notes'
+];
+
+export const editable_fields__event_exhibit_tracking = [
+    'exhibitor_notes',
+    'responses_json',
+    'data_json',
+    'enable',
+    'hide',
+    'priority',
+    'sort',
+    'group',
+    'notes'
+];