Restore Event Session search stability and advance platform-wide string ID standardization

- Restored Event Session search by standardizing on 'event_id' for Dexie queries and implementing dual-layer filtering (local + API guard) to prevent broad results from clobbering filtered views.
- Advanced String-Only ID Standardization (Phase 2) by updating generic object processors across all event library modules to support both base IDs and legacy '_random' variants.
- Refactored Event Presenter and Presentation components to support standardized '_id_li' props while maintaining backward compatibility.
- Standardized common helper identifiers to snake_case (e.g., 'prevent_default') in the Events module.
- Verified Staff and Poster email notification logic in the Bulletin Board module.
- Updated .gitignore and cleaned up test artifacts.

src/routes/events/ae_comp__event_presentation_obj_li.svelte

@@ -463,8 +463,8 @@
                     {#if event_presentation_obj?.event_presentation_id}
                         <Comp_event_presenter_obj_li
                             link_to_type={'event_presentation'}
-                            link_to_id={event_presentation_obj?.event_presentation_id}
-                            event_presenter_id_random_li={[]}
+                            link_to_id={event_presentation_obj.event_presentation_id}
+                            event_presenter_id_li={[]}
                             log_lvl={2}
                         ></Comp_event_presenter_obj_li>
                     {/if}