feat: upgrade launcher WebSocket to V3 protocol

- New element_websocket_v3.svelte:
  - URL path /v3/ws/group/{id}/client/{id}
  - Auth via ?api_key=...&jwt=... query params (browsers can't set WS headers)
  - Strict WS_Message_V3 schema: msg_type + target fields
  - 45s heartbeat to maintain Redis presence TTL
  - Self-echo detection via from_id (server-stamped)
  - Target 'group' (was 'all'), 'direct' (was 'dm')
- launcher/+layout.svelte:
  - Swap Element_websocket_v2 -> Element_websocket_v3
  - Add api_key and jwt props for V3 auth
  - Fix handle_ws_recv: type -> msg_type (V3 schema)
  - Remove unused 'type' prop passed to element

src/routes/events/[event_id]/(launcher)/launcher/+layout.svelte

@@ -54,7 +54,7 @@
     import Launcher_cfg from '../launcher_cfg.svelte';
     import Launcher_menu from '../launcher_menu.svelte';
     import Launcher_session_view from '../launcher_session_view.svelte';
-    import Element_websocket_v2 from '$lib/elements/element_websocket_v2.svelte';
+    import Element_websocket_v3 from '$lib/elements/element_websocket_v3.svelte';
 
     // *** Set initial variables
     // NOTE: Derived from data.account_id (prop) instead of $slct.account_id (store)
@@ -288,7 +288,8 @@
 
     function handle_ws_recv(ws_recv_status: any) {
         if (log_lvl) console.log('*** handle_ws_recv() ***', ws_recv_status);
-        if (ws_recv_status.type == 'cmd' && ws_recv_status.cmd) {
+        // V3 schema uses msg_type instead of type
+        if (ws_recv_status.msg_type == 'cmd' && ws_recv_status.cmd) {
             let cmd = ws_recv_status.cmd;
             if ($events_loc.launcher.controller != 'remote') return;
 
@@ -1001,15 +1002,16 @@
 </Modal>
 
 {#if $events_loc.launcher.controller_group_code && $events_loc.launcher.ws_connect}
-    <Element_websocket_v2
+    <Element_websocket_v3
         {log_lvl}
         bind:ws_connect={$events_loc.launcher.ws_connect}
         bind:ws_connect_status={$events_sess.launcher.ws_connect_status}
         ws_server={$ae_api.fqdn}
+        api_key={$ae_api.api_secret_key}
+        jwt={$ae_loc.jwt}
         bind:group_id={$events_loc.launcher.controller_group_code}
         bind:client_id={$events_loc.launcher.controller_client_id}
         bind:cmd={$events_sess.launcher.controller_cmd}
-        type={'cmd'}
         bind:trigger_send={$events_sess.launcher.controller_trigger_send}
         bind:trigger_connect={$events_sess.launcher.trigger__ws_connect}
         bind:trigger_disconnect={$events_sess.launcher.trigger__ws_disconnect}