ALL EDITORS V448 - SAVE GAME ALWAYS IN THE MENU, JOIN CAMPAIGN JOINS THE PARTY
(V447 base: player Save Game relay, Resume shows the saves, no pause, frozen
 files. README_V447_PLAYER_SAVE_RESUME_SAVES_NO_PAUSE.txt still applies.)

INSTALL (HOST PC)
  Close every BG2 window, extract the whole ZIP, run SETUP_IN_GAME_ACCOUNTS.bat
  (or UI Interface Editor > IN-GAME ACCOUNTS / SETUP > INSTALL / REPAIR V448).
  Read the message at the end: it says whether the account save folders are on.

1. SAVE GAME IS ALWAYS IN THE IN-GAME MENU (Esc / Options)
  Your screenshot showed an empty third button on the left. That was the old
  V404/V445 Save button: disabled on the host while no campaign is selected,
  and always disabled on a joined player's game - its dimmed text is
  practically invisible on that frame. It also meant V446/V447 had not been
  applied on that PC (setup stopped, see 3).
  V448: whatever is in that slot is replaced by ONE Save Game button that is
  always clickable and whose label can never be blank (BG2's own SAVE GAME
  text in your language, else "SAVE GAME").
  - Host / single player: BG2's Save screen. Saving works even with no
    campaign selected (then named "Campaign Progress" unless you type a name).
  - Joined player: the host's game saves the party as that player's own save
    (V447) - the result appears in the multiplayer chat.

2. JOIN CAMPAIGN JOINS THE CHOSEN CAMPAIGN'S PARTY
  Multiplayer > JOIN CAMPAIGN > SoA / ToB / TBP II:
  - that campaign is hosted on THIS PC (another account's window hosts it)
    -> this account joins that party directly.
  - otherwise -> BG2's LAN search as before (hosts on other PCs), else
    Create Game.
  Why it did not join before: BG2's LAN list fills in over a few seconds, but
  the picker looked at it immediately, saw "0 games" and opened Create Game.
  The other way (campaign logo > Multiplayer, V444) keeps working.

3. SETUP NO LONGER STOPS
  - Any BaldurII.exe build: setup always completes. Only the verified build
    (V445) gets the per-account folders save_/mpsave_/mpbsave_<account>; any
    other build keeps BG2's shared save folders, where saves stay separated
    by account name (as before V445). The final message says which.
  - If your UI.MENU's Save screens differ from what V446 expects, setup still
    completes; V448 covers saving without that conversion.
  - Re-running setup gives a byte-identical UI.MENU; upgrading from V447 or
    from a V444-era UI.MENU gives the same result as a fresh install.

UI INTERFACE EDITOR
  Same V448 installer; CHECK ACCOUNT SETUP STATUS also reports JOIN CAMPAIGN;
  the install message reports whether account save folders are on.

CHECKS (offline)
  python -m unittest test_v448_save_button_campaign_join test_v447_save_resume test_v444_ui_editor_account_setup -v
NOT TESTED HERE: real BG2 windows on Windows.
