Say how to launch an app, and record how the way in was found

F then 7 opens the F4HWN APPS menu and MENU runs the selected app, which is upstream's own wording in UVStudio's locales/en.js and what App/apps/app_menu.c does (KEY_MENU on an installed row calls APP_LaunchOverlay, which runs until the app exits; EXIT leaves). Verified in the emulator with Tetris.app installed through the page's endpoint: F,7 reads the app region eight times and shows the boxed menu; MENU reads once inside slot 0's code and the game's screen replaces the radio's; DOWN moves the piece and the game is still there two seconds later. The page's own hint now says so.

Worth recording: twenty keys short and long, the whole 79-entry settings menu and the multiboot menu all left the app region untouched -- the multiboot menu reads firmware slots, not apps. The entry point was written down in the flasher's translation file, not in the firmware source: when a feature's way in is missing, the host tool that installs it is the document.

tools/webui.py

@@ -979,7 +979,8 @@ def render_index(scale: int) -> str:
     <button id="appask" title="ask the running firmware what it sees in each app slot">Ask the radio</button>
     <span class="hint">the Labs edition's apps live in the same external flash (16 slots
     from 0x102000; the firmware's menu lists the first eight, numbered 1..8). Pick a .app for a slot to
-    install it — no serial port and no browser permission are involved</span>
+    install it — no serial port and no browser permission are involved — then press F then 7 on the
+    radio and MENU to run it</span>
   </div>
   <table id="apptable"><tbody></tbody></table>
   <div class="screenwrap" id="screenwrap">