fix(client): resolve all gdlint warnings — zero warnings policy

Fix 354 gdlint warnings across 65 files: 194 class-definitions-order
(reorder declarations), 138 max-line-length (split long lines),
22 code issues (unused args, no-else-return, naming). Update .gdlintrc
to exclude addons/ and raise max-public-methods for test files.
No logic changes — declaration order, whitespace, and naming only.

Ticket: #783

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client/tests/test_rendering.gd

@@ -281,7 +281,8 @@ func test_entity_renderer_npc_uses_unknown_teal() -> void:
 
 func test_entity_renderer_object_uses_grey() -> void:
 	var renderer := _make_entity_renderer()
-	var obj := [{"entity_id": 3, "x": 1.0, "y": 1.0, "z": 0, "kind": {"variant": "Object", "data": null}, "visibility": "Forward"}]
+	var obj := [{"entity_id": 3, "x": 1.0, "y": 1.0, "z": 0,
+		"kind": {"variant": "Object", "data": null}, "visibility": "Forward"}]
 	renderer.update_entities(obj)
 	var node = renderer.entity_nodes[3] as Sprite2D
 	assert_that(node.self_modulate).is_equal(Constants.ENTITY_COLOR_OBJECT)