feat: converter accepts the constructs of goodluke and SaintlyCorruption

`init -490 screen`, `import x as y` and `from m import A as B`, classes with @renpy.pure, pickle hooks
on classes, `*` items in tuples and lists, generator functions (yield statements; the player runs them
to the end), multi-line expressions that need brackets, Null() and Animation() images, images given as
expressions (`"path/{}.png".format(x)`, f-strings), window statements in init, `offset` in ATL, input
widgets with their values and the focus/confirm actions, `continue` and `break` in screens, `drag`
and DiamondBox-style `fixed` with cell_size, `getattr(...)()` calls, transforms called with arguments,
and the whitelist for the new runtime. JSON files of a game are shipped as data files. Also fixes
blocking_names failing on a call of a call during full conversion.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

backend/tests/test_renpy_universal.py

@@ -235,3 +235,33 @@ def test_init_if_has_live2d_keeps_only_the_else_branch_and_crop_call_glued_to_a_
 def test_static_atl_line_with_a_spaced_crop_tuple():
     data = parse('image plap:\n    "base"\n    crop (1697,54, 172, 94)\nimage slurp:\n    "base"\n    crop (1, 2, 3, 4) xanchor 0.5\n')
     assert not data.blockers
+
+
+def test_priority_screen_continue_and_offset_with_computed_halves():
+    data = parse('init -490 screen s(items):\n    for item in items:\n        if item == 1:\n            continue\n        text "[item]"\n'
+                 'transform lift:\n    linear 0.2 offset (0, -LIFT)\nlabel start:\n    call screen s([1, 2])\n')
+    assert "s" in data.screens
+    loop = data.screens["s"]["body"][0]
+    assert loop["c"] == "for" and loop["body"][0]["branches"][0]["body"] == [{"c": "continue"}]
+    assert not data.blockers
+
+
+def test_import_alias_decorated_class_null_image_window_in_init_and_offset_line():
+    from app.converter import pyexpr
+
+    code = pyexpr.parse_stmts("import time as stamp\nfrom renpy.text.text import Text as RenpyText\n"
+                              "@renpy.pure\nclass Typing(VariableInputValue):\n    pass\n")
+    assert code[0] == {"op": "set", "t": {"k": "name", "id": "stamp"}, "v": {"k": "name", "id": "time"}}
+    assert code[1]["v"] == {"k": "name", "id": "Text"} and code[2]["op"] == "class"
+    data = parse('init 1:\n    image blank = Null()\ninit -1:\n    window hide\ntransform t:\n    offset (0, 0)\n    on idle:\n        linear 0.2 offset (1, 2)\n')
+    assert data.images["blank"] == {"color": "#00000000"} and not data.blockers
+
+
+def test_starred_tuple_items_and_pickle_hooks_are_accepted():
+    from app import pgvn
+    from app.converter import pyexpr
+
+    code = pyexpr.parse_stmts("pair = (first, *rest)\nclass Scene:\n    def __setstate__(self, state):\n        pass\n    def run(self):\n        return 1\n")
+    pgvn.statements(code)
+    assert code[0]["v"]["v"][1] == {"k": "star", "v": {"k": "name", "id": "rest"}}
+    assert [m["name"] for m in code[1]["body"]] == ["run"]