Add extended battle HUD visual coverage

tests/drivers/fill_extended_auto_menu_test.lua

@@ -0,0 +1,53 @@
+-- Visual and behavioral acceptance for the adaptive BATTLE BG menu rule.
+return function(game)
+  local U = dofile("tests/drivers/util.lua")
+  local DIR = os.getenv("SHOT_DIR") or "/tmp/shots"
+
+  love.window.setMode(1920, 1080, { resizable = true })
+  U.wait(3)
+
+  local options = game.save.options
+  options.battleLayout = "wide"
+  options.battleFit = "fixed"
+  options.battleHud = "extended"
+  options.battleBg = "black"
+
+  local menu = require("src.ui.Screens").push(game, "OptionsMenu")
+  local fitRow, bgRow
+  local bgIndex
+  for i, row in ipairs(menu.rows) do
+    if row.id == "battleFit" then fitRow = row end
+    if row.id == "battleBg" then bgRow, bgIndex = row, i end
+  end
+  assert(fitRow and bgRow and bgIndex, "battle size/background rows are present")
+
+  fitRow.step(game, 1)
+  assert(options.battleFit == "fill", "battle size switched to FILL")
+  assert(options.battleBg == "white", "FILL + EXTENDED normalized background to WHITE")
+  assert(bgRow.value(game) == "AUTO", "adaptive background is labeled AUTO")
+  assert(bgRow.step(game, 1) == false, "AUTO background row is locked")
+  assert(options.battleBg == "white", "locked AUTO retains the WHITE value")
+
+  menu.index = bgIndex
+  menu.scroll = math.max(0, bgIndex - 5)
+  U.wait(2)
+  local autoPath = DIR .. "/fill_extended_auto_menu.png"
+  os.remove(autoPath)
+  local ok = U.shot(game, autoPath)
+
+  fitRow.step(game, -1)
+  assert(options.battleFit == "fixed", "battle size switched back to FIXED")
+  assert(bgRow.value(game) == "WHITE", "FIXED exposes the stored WHITE choice")
+  assert(bgRow.step(game, 1) == true and options.battleBg == "black",
+    "FIXED can select BLACK")
+  assert(bgRow.step(game, 1) == true and options.battleBg == "world",
+    "FIXED can select WORLD")
+  U.wait(2)
+  local fixedPath = DIR .. "/fixed_extended_background_choices.png"
+  os.remove(fixedPath)
+  ok = U.shot(game, fixedPath) and ok
+
+  U.log(ok and "FILL_EXTENDED_AUTO_MENU_PASS"
+    or "FILL_EXTENDED_AUTO_MENU_FAIL")
+  love.event.quit(ok and 0 or 1)
+end