chore: add gitignore and build configuration

.gitignore

@@ -0,0 +1,13 @@
+# compiled lua
+*.luac
+
+# coverage
+luacov.*
+
+# run / save output
+*.out
+
+# os / logs / env
+.DS_Store
+*.log
+.env

warren.lua

@@ -0,0 +1,38 @@
+-- Headless entry point. Examples:
+--   lua warren.lua --seed 42 --auto 50
+--   lua warren.lua --seed 7 --auto 30 --save run.sav
+--   lua warren.lua --load run.sav
+
+local scriptDir = arg[0]:match("^(.*)[/\\]") or "."
+package.path = scriptDir .. "/src/?.lua;" .. scriptDir .. "/../src/?.lua;" .. package.path
+
+local Game = require("game")
+
+local function parseArgs(argv)
+  local opts = { seed = os.time() & 0xFFFF, auto = 0 }
+  local i = 1
+  while i <= #argv do
+    local flag = argv[i]
+    if flag == "--seed" then opts.seed = math.tointeger(tonumber(argv[i + 1])); i = i + 2
+    elseif flag == "--auto" then opts.auto = math.tointeger(tonumber(argv[i + 1])); i = i + 2
+    elseif flag == "--save" then opts.save = argv[i + 1]; i = i + 2
+    elseif flag == "--load" then opts.load = argv[i + 1]; i = i + 2
+    else i = i + 1 end
+  end
+  return opts
+end
+
+local opts = parseArgs(arg)
+local game = opts.load and Game.load(opts.load) or Game.new(opts.seed)
+
+for _ = 1, opts.auto do
+  if not game.player:isAlive() then break end
+  game:autoStep()
+end
+
+io.write(game:render(), "\n")
+
+if opts.save then
+  game:save(opts.save)
+  io.write("saved to " .. opts.save .. "\n")
+end