pres_mgmt config: remove legacy launcher option, add back button + dirty state to config UI

- Remove show__launcher_link_legacy from PressMgmtRemoteCfg, PresMgmtLocState, and
  pres_mgmt_loc_defaults — the Flask/legacy launcher is retired
- Sync function now hardcodes hide__launcher_link_legacy=true (always hidden)
- Config page: back button to pres_mgmt, save buttons disabled until changes made
- Fix {#each} key expressions in config page
- Migrate e_app_access_type and element_manage_event_file_li to pres_mgmt_loc store
- Add temporary svelte type augments file (src/types/)

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

src/lib/elements/element_manage_event_file_li.svelte

@@ -23,6 +23,7 @@ import {
     events_slct,
     events_trigger
 } from '$lib/stores/ae_events_stores';
+import { pres_mgmt_loc } from '$lib/stores/ae_events_stores__pres_mgmt.svelte';
 import { events_func } from '$lib/ae_events/ae_events_functions';
 import AE_Comp_Hosted_Files_Download_Button from '$lib/ae_core/ae_comp__hosted_files_download_button.svelte';
 import {
@@ -76,7 +77,7 @@ let {
 let ae_promises: key_val = $state({});
 let ae_tmp: key_val = $state({});
 ae_tmp.show__file_li = true;
-ae_tmp.show__direct_download = $events_loc.pres_mgmt.show__direct_download;
+ae_tmp.show__direct_download = pres_mgmt_loc.current.show__direct_download;
 // let ae_triggers: key_val = {};
 
 onMount(() => {
@@ -674,8 +675,8 @@ async function handle_convert_pdf_to_image(event_file_obj: key_val) {
                                                     value={null}
                                                     selected={!event_file_obj.file_purpose}
                                                     >-- purpose not set --</option>
-                                                {#if $events_loc.pres_mgmt?.file_purpose_option_kv}
-                                                    {#each Object.entries($events_loc.pres_mgmt.file_purpose_option_kv as any) as [key, file_purpose_option] (key)}
+                                                {#if pres_mgmt_loc.current.file_purpose_option_kv}
+                                                    {#each Object.entries(pres_mgmt_loc.current.file_purpose_option_kv as any) as [key, file_purpose_option] (key)}
                                                         <option
                                                             value={key}
                                                             selected={event_file_obj.file_purpose ===