Replace M* table-wrapper classes with typed Resources; add type hints

Two related cleanups from the best-practice audit:

Task 3 — typed Resources instead of MBase / MScene / MLevel / MSetting

The old model classes wrapped the godot_db_manager Table API: each row
read went through table.get_data_at_row_idx(int), Cell.get_data(),
and 'as int' / 'as String' casts that don't actually parse anything
in Godot 4. m_value, m_lock, m_label, ... members shadowed the cell
indirection. Setters round-tripped through table.edit_data() +
Global.database.save_db(). That's a lot of plumbing for what is, in
the end, three flat tables of static strings.

Introduce three @export-typed Resources:
  db/scene_entry.gd     class_name SceneEntry
  db/level_entry.gd     class_name LevelEntry
  db/settings_data.gd   class_name SettingsData

Rewrite scripts/Database.gd so Database.DB holds:
  settings: SettingsData
  levels:   Array[LevelEntry]
  scenes:   Array[SceneEntry]

Build them once at startup from ahog.json, and serialise back to the
same JSON shape on save() so existing progress files keep working.
LevelEntry carries its own object_to_find / object_finding / reset
methods (talking to Global.database for cross-table lookups), and
SceneEntry carries its own mesh_path / audio_sound. Per-scene
dissolve state (value, tick_reference, dissolved) lives on
SceneEntry as non-exported runtime fields.

Delete db/MBase.gd / db/MScene.gd / db/MLevel.gd / db/MSetting.gd.

Update consumers:
- scripts/Setting.gd: read/write Global.database.settings directly,
  call Global.database.save() after each setter.
- scenes/levels/Levels.gd: iterate Global.database.scenes_for_level(
  current_scene_int) instead of mscene.new(i) for every row; scene
  state reads (scene.lock, scene.mesh, scene.counter, ...) replace
  scene.lock() / scene.mesh() / scene.counter() method calls; runtime
  dissolve state lives on the SceneEntry instance instead of mutable
  m_value / m_tick_reference members on MScene; 'dissolved' flag
  replaces set_mesh(null) signalling.
- scenes/UI/choose_scenes/ChooseScene.gd: iterate Global.database
  .levels; level.name / level.thumb property access in place of
  level.name() / level.thumbnail(). configure_reset() loses its
  redundant index argument (LevelEntry knows its own index).
- scripts/event.gd: _on_reset_level signature now takes LevelEntry,
  reset path drops index forwarding.

Task 2 — type hints across the remaining scripts

scripts/Global.gd, scenes/Main.gd, scenes/UI/ending/Ending.gd,
scenes/UI/loading/Loading.gd, scenes/UI/settings/Settings.gd: add
typed parameters and -> return annotations. current_scene_int is now
'int = -1' (sentinel) so callers don't fall into Variant comparisons;
event.gd:_on_reset_level resets it to -1 instead of null.
Settings.gd no longer wraps button_pressed in int() before passing to
the now-typed bool setters.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/event.gd

@@ -22,12 +22,12 @@ static func _on_home_pressed() -> void:
 	Global.current_scene_int = 1
 	Global.goto_scene("res://scenes/levels/home/Home.tscn")
 
-static func _on_reset_level(level, node: String, index: int, parent) -> void:
+static func _on_reset_level(level: LevelEntry, node: String, index: int, parent) -> void:
 	Global.current_scene_int = index
 	level.reset()
-	parent.configure_reset(level, node, index, true)
+	parent.configure_reset(level, node, true)
 	parent.configure_counter(level, node)
-	Global.current_scene_int = null
+	Global.current_scene_int = -1
 
 static func _on_main_scene_pressed() -> void:
 	Global.goto_scene("res://scenes/Main.tscn")