Add settings screen and adult space with progress report and save export/restore (0.4.0)

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

tests/profiles/test_adult_gate.gd

@@ -0,0 +1,33 @@
+extends GutTest
+## Tests d'AdultGate : le calcul est dans les bornes et la reponse est exacte.
+
+
+func test_challenge_is_within_bounds_and_answer_matches() -> void:
+    var rng := RandomNumberGenerator.new()
+    rng.seed = 42
+    for _i in range(50):
+        var challenge := AdultGate.make_challenge(rng)
+        assert_between(challenge["a"], AdultGate.MIN_FACTOR_A, AdultGate.MAX_FACTOR_A)
+        assert_between(challenge["b"], AdultGate.MIN_FACTOR_B, AdultGate.MAX_FACTOR_B)
+        assert_eq(challenge["answer"], challenge["a"] * challenge["b"])
+
+
+func test_same_seed_gives_same_challenge() -> void:
+    var first := RandomNumberGenerator.new()
+    first.seed = 7
+    var second := RandomNumberGenerator.new()
+    second.seed = 7
+    assert_eq(AdultGate.make_challenge(first), AdultGate.make_challenge(second))
+
+
+func test_is_correct_accepts_exact_answer_with_spaces() -> void:
+    var challenge := {"a": 13, "b": 7, "answer": 91}
+    assert_true(AdultGate.is_correct(challenge, "91"))
+    assert_true(AdultGate.is_correct(challenge, " 91 "))
+
+
+func test_is_correct_rejects_wrong_or_non_numeric() -> void:
+    var challenge := {"a": 13, "b": 7, "answer": 91}
+    assert_false(AdultGate.is_correct(challenge, "90"))
+    assert_false(AdultGate.is_correct(challenge, ""))
+    assert_false(AdultGate.is_correct(challenge, "quatre-vingt-onze"))