fix(pres_mgmt): hidden files now visible in Manage Files without manual refresh

Background file loads for session, presentation, and presenter were using the
default hidden='not_hidden', so hidden files never reached Dexie. The Manage
Files liveQuery reads straight from Dexie, making hidden files completely
invisible until the Refresh button was clicked (which already used hidden='all').

The Launcher is unaffected — it has always had a render-time guard that hides
files with event_file_obj.hide unless show_content__hidden_files is enabled.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/ae_events/ae_events__event_presentation.ts

@@ -181,6 +181,8 @@ async function _handle_nested_loads(
                 for_obj_type: 'event_presentation',
                 for_obj_id: current_presentation_id,
                 enabled,
+                // WHY: include hidden files so Manage Files UI can show/unhide them.
+                hidden: 'all',
                 limit: 25,
                 try_cache,
                 log_lvl

src/lib/ae_events/ae_events__event_presenter.ts

@@ -102,6 +102,8 @@ async function _refresh_presenter_id_background({
                     for_obj_type: 'event_presenter',
                     for_obj_id: event_presenter_id,
                     enabled: 'all',
+                    // WHY: include hidden files so Manage Files UI can show/unhide them.
+                    hidden: 'all',
                     limit: 25,
                     try_cache: false,
                     log_lvl
@@ -284,6 +286,8 @@ async function _refresh_presenter_li_background({
                         for_obj_type: 'event_presenter',
                         for_obj_id: p.id,
                         enabled: 'all',
+                        // WHY: include hidden files so Manage Files UI can show/unhide them.
+                        hidden: 'all',
                         limit: 25,
                         try_cache: false,
                         log_lvl: 0

src/lib/ae_events/ae_events__event_session.ts

@@ -278,6 +278,10 @@ async function _handle_nested_loads(
                 for_obj_type: 'event_session',
                 for_obj_id: current_session_id,
                 enabled,
+                // WHY: must include hidden files so the Manage Files UI can show and unhide them.
+                // The default 'not_hidden' was causing hidden files to never reach Dexie,
+                // making them invisible in the manage list until a manual Refresh.
+                hidden: 'all',
                 limit: 15,
                 try_cache,
                 log_lvl