Tolerate missing terminal punctuation in dictée answers

Manual test: the Piper voice (previous commit) is now intelligible,
but typing exactly what's heard ("Les petits chats dorment", no
period) was rejected. The provisional audio never vocalizes
punctuation, so nothing tells the child to add it — penalizing its
absence punishes information they were never given.

DictationAnalyzer now strips terminal punctuation (. ! ? …) from both
sides before comparing, in the exact-match/variant check and before
word alignment, without touching punctuation elsewhere in the
sentence. A real error on the last word is still caught (added test).

A scene-level test reproducing the exact reported interaction
(tests/exercises/test_exercise_host_dictation.gd) failed before the
fix and passes after.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/exercises/test_exercise_host_dictation.gd

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+extends GutTest
+## Reproduction d'un bug signale manuellement via exercise_host : la dictee
+## "Les petits chats dorment." tapee exactement comme entendue n'etait pas
+## validee comme correcte.
+
+var _profile_id: String = ""
+
+
+func before_each() -> void:
+    _profile_id = ProfileManager.create_profile("Test", "CE1")
+    ProfileManager.select_profile(_profile_id)
+    GameManager.pending_mission_id = "mission_03_clairiere_echo"
+
+
+func after_each() -> void:
+    ProfileManager.delete_profile(_profile_id)
+    GameManager.pending_mission_id = ""
+
+
+func test_exact_target_text_is_validated_as_correct() -> void:
+    var host: Control = await _ready_host()
+    var exercise_scene: Control = host.get_node("%ExerciseContainer").get_child(0)
+    var exercise: Dictionary = host.get_current_exercise()
+    assert_eq(exercise["target_text"], "Les petits chats dorment.")
+
+    (exercise_scene.get_node("%TextEdit") as LineEdit).text = exercise["target_text"]
+    exercise_scene.get_node("%ValidateButton").pressed.emit()
+    await wait_process_frames(1)
+
+    assert_eq(_feedback_title(host), UIText.get_text("feedback_panel.correct_title"))
+
+
+## "J'entends parfaitement mais ne valide pas" : l'audio ne fait entendre
+## aucune ponctuation, donc l'enfant qui ecrit exactement ce qu'il entend
+## (sans le point final) doit tout de meme etre valide.
+func test_missing_final_period_is_still_validated_as_correct() -> void:
+    var host: Control = await _ready_host()
+    var exercise_scene: Control = host.get_node("%ExerciseContainer").get_child(0)
+
+    (exercise_scene.get_node("%TextEdit") as LineEdit).text = "Les petits chats dorment"
+    exercise_scene.get_node("%ValidateButton").pressed.emit()
+    await wait_process_frames(1)
+
+    assert_eq(_feedback_title(host), UIText.get_text("feedback_panel.correct_title"))
+
+
+func _ready_host() -> Control:
+    var host: Control = load("res://scenes/exercises/exercise_host.tscn").instantiate()
+    add_child_autofree(host)
+    await wait_process_frames(1)
+
+    var overlay: Control = host.get_node("%OverlayContainer")
+    overlay.get_child(0).continued.emit()
+    await wait_process_frames(1)
+    return host
+
+
+func _feedback_title(host: Control) -> String:
+    var overlay: Control = host.get_node("%OverlayContainer")
+    var feedback: Control = overlay.get_child(overlay.get_child_count() - 1)
+    var title_label: Label = feedback.get_node("%TitleLabel")
+    return title_label.text

tests/exercises/test_exercise_host_dictation.gd.uid

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+uid://dcas0r0cf6k7u