feat: _() strings and screen texts become translatable strings; search looks in all states; stutter hint

show text _("...") and literal screen texts are listed in Names and menu; typing in search switches the filter from To do to All; the translator is told how stutters are spelled.

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

backend/tests/test_translation.py

@@ -96,3 +96,26 @@ def test_entries_page_locates_a_line_in_the_filtered_list(manifest):
     assert tr.entries_page(m, "ru", state="todo", locate=first.tid)["located"] == 0
     assert tr.entries_page(m, "ru", locate="")["located"] is None
     assert tr.entries_page(m, "ru", kind="strings", locate="Эйлин")["located"] is not None
+
+
+def _mark(text):
+    return {"k": "call", "f": {"k": "name", "id": "_"}, "a": [{"k": "const", "v": text}]}
+
+
+def test_marked_strings_and_screen_texts_become_translatable_strings():
+    body = [
+        {"op": "show", "img": {"textExpr": _mark("Do you want a short tutorial?")}},
+        {"op": "python", "code": [{"k": "assign", "value": _mark("Hi, [name]!")}]},
+        {"op": "show", "img": {"textExpr": _mark("")}},           # empty: nothing to translate
+        {"op": "show", "img": {"textExpr": _mark("42")}},         # no letters: not text
+        {"op": "show", "img": {"textExpr": {"k": "call", "f": {"k": "name", "id": "other"},
+                                             "a": [{"k": "const", "v": "Not marked"}]}}},
+    ]
+    screens = {"menu": {"body": [
+        {"w": "text", "args": [{"k": "const", "v": "Preferences"}], "props": {}, "body": []},
+        {"w": "textbutton", "args": [{"k": "const", "v": "Quit"}], "props": {}, "body": []},
+        {"w": "text", "args": [{"k": "name", "id": "title"}], "props": {}, "body": []},   # variable
+        {"w": "add", "args": [{"k": "const", "v": "bg.png"}], "props": {}, "body": []},   # not text
+    ]}}
+    assert tr.marked_strings([{"name": "start", "body": body}]) == ["Do you want a short tutorial?", "Hi, [name]!"]
+    assert tr.marked_strings(screens) == ["Preferences", "Quit"]