Follow the GDScript style guide in every script

- Types on every parameter, return value and variable, and snake_case names
  (the player name limit is the constant MAX_NAME_LENGTH).
- Spelling fixes: *_triggered, character_selected, separator, caught_errors.
  The server's catched_errors key stays as the server sends it.
- Signals are connected with signal.connect() instead of by name.
- Code is ordered signals, constants, exported vars, vars, @onready vars,
  functions, with @onready on one line and two blank lines between functions.
- Every script starts with a ## description. Template comments, old LOC notes
  and commented-out code are gone, apart from the local play code.
- Lines are at most 100 characters, apart from the local play path.
- The screenshot tour turns off the blinking text cursor so pictures match.

tests/unit/test_list_row.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## ListRow: text, alternating backgrounds and wrapping.
 
 
 func _background(list_row: ListRow) -> Color:

tests/unit/test_music_player_time.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## How the music player shows a song's time, including the hidden parts.
 
 var _music_player: MusicPlayer
 var _hide_beginning: bool

tests/unit/test_music_server_client.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## MusicServerClient: which paths it asks for and how it handles the answers.
 
 var _server: FakeHttpTransport
 
@@ -115,7 +116,8 @@ func test_mark_song_played_sends_put() -> void:
 
 
 func test_character_name_is_url_encoded() -> void:
-	MusicServerClient.fetch_character_image("Paper Mario.png", func(_body: PackedByteArray) -> void: pass)
+	MusicServerClient.fetch_character_image("Paper Mario.png",
+			func(_body: PackedByteArray) -> void: pass)
 
 	assert_array(_server.requested_paths).contains_exactly(["/character?name=Paper%20Mario.png"])
 

tests/unit/test_player_object.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## PlayerObject: points, and the first point, match point and winner signals.
 
 var _winning_score: int
 var _player: PlayerObject
@@ -20,7 +21,7 @@ func test_first_point_triggers_first_point_signal() -> void:
 	_player.add_point()
 
 	assert_int(_player.player_score).is_equal(1)
-	await assert_signal(_player).is_emitted("first_point_triggerd")
+	await assert_signal(_player).is_emitted("first_point_triggered")
 	await assert_signal(_player).is_emitted("player_point_given")
 
 
@@ -30,7 +31,7 @@ func test_one_point_from_winning_triggers_match_point() -> void:
 
 	_player.add_point()
 
-	await assert_signal(_player).is_emitted("match_point_triggerd")
+	await assert_signal(_player).is_emitted("match_point_triggered")
 
 
 func test_reaching_winning_score_triggers_winner() -> void:
@@ -41,7 +42,7 @@ func test_reaching_winning_score_triggers_winner() -> void:
 	_player.add_point()
 
 	assert_int(_player.player_score).is_equal(3)
-	await assert_signal(_player).is_emitted("winner_triggerd")
+	await assert_signal(_player).is_emitted("winner_triggered")
 
 
 func test_score_does_not_go_past_winning_score() -> void:
@@ -91,7 +92,7 @@ func test_dropping_back_to_zero_allows_first_point_again() -> void:
 
 	_player.add_point()
 
-	await assert_signal(_player).is_emitted("first_point_triggerd")
+	await assert_signal(_player).is_emitted("first_point_triggered")
 
 
 func test_reset_points() -> void:
@@ -125,7 +126,7 @@ func test_winning_score_of_one_is_won_with_first_point() -> void:
 
 	_player.add_point()
 
-	await assert_signal(_player).is_emitted("winner_triggerd")
+	await assert_signal(_player).is_emitted("winner_triggered")
 
 
 func test_first_point_is_match_point_when_winning_score_is_two() -> void:
@@ -134,5 +135,5 @@ func test_first_point_is_match_point_when_winning_score_is_two() -> void:
 
 	_player.add_point()
 
-	await assert_signal(_player).is_emitted("match_point_triggerd")
+	await assert_signal(_player).is_emitted("match_point_triggered")
 	assert_bool(_player.is_first_point).is_false()

tests/unit/test_playlist.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## Playlist: moving through the songs, answering them and keeping points.
 
 var _server: FakeHttpTransport
 var _add_to_stats: bool

tests/unit/test_search.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## How the search popup finds and orders matching soundtracks.
 
 const SearchWindowScript: GDScript = preload("res://search_popup.gd")
 
@@ -36,7 +37,8 @@ func test_ignores_spaces() -> void:
 
 
 func test_and_matches_ampersand() -> void:
-	assert_array(_search.find_matches("mario and luigi")).contains(["Mario & Luigi: Superstar Saga"])
+	assert_array(_search.find_matches("mario and luigi")) \
+			.contains(["Mario & Luigi: Superstar Saga"])
 
 
 func test_accented_letters_match_plain_letters() -> void:

tests/unit/test_settings.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## Settings: the version number.
 
 
 func test_version_comes_from_project_settings() -> void:

tests/unit/test_song_object.gd

@@ -1,4 +1,5 @@
 extends GdUnitTestSuite
+## SongObject: what it shows before and after the answer, and its points.
 
 var _is_debug: bool
 var _song: SongObject