#84: move 215 root files into a folder hierarchy

Everything lived in one flat directory, so a diff gave no clue what area it
touched and finding the file you wanted meant knowing its exact name. Twelve
folders now, grouped by what a thing IS rather than what type it is - a
vessel's definition, its component scenes and its upgrade resources sit
together, because that is the set you read when you change one of them.

  buildings  core  controllers  enemies  logistics  planets
  resources  shaders  surface  ui  vessels  vfx  world

332 files moved and every res:// reference rewritten - 306 files touched,
including the autoload and main-scene paths in project.godot. Nothing renamed:
this is purely where files sit, so the diff is a pile of pure moves and no
behaviour is buried in it. ui_theme.tres, icon.svg and web_shell.html stay at
the root, where Godot and the export preset expect them.

Verified three ways, because a suite alone would not have caught all of it:
the full 117 pass, the web export builds clean, and the game renders.

The export is why that matters. The FIRST export after the move failed with
"Attempt to open script 'res://GameState.gd'" - the old path - while
project.godot on disk plainly said res://core/GameState.gd. That is this
project's documented Android FUSE mtime trap: Godot served a cached copy of a
file whose content had changed. A `touch` fixed it. Nothing in the test suite
would have found that, because the suite runs from a copy on a native
filesystem - the one place the bug cannot happen.

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

CaptureLabel.gd

@@ -1,45 +0,0 @@
-extends Label
-
-# Polls GameState directly, same convention as ResourceReadout, so it stays
-# correct without anyone having to push updates into it. Hidden
-# entirely when the current planet has no capture points (e.g. no setup
-# resolved for it) rather than showing "0/0".
-
-# A direct script preload, not the bare "PlanetDefinitions" global class_name
-# - the same load-order hazard PlanetSurfaceController's setup_host comment
-# already documents: the global identifier is only guaranteed registered
-# after an editor/import pass, a direct preload never depends on that.
-const PLANET_DEFINITIONS = preload("res://PlanetDefinitions.gd")
-
-var _was_conquered: bool = false
-
-
-func _process(_delta: float) -> void:
-	var planet_id: String = GameState.planet_id
-	var total: int = GameState.total_capture_points(planet_id)
-	if total <= 0:
-		visible = false
-		return
-	visible = true
-
-	var conquered: bool = GameState.is_planet_conquered(planet_id)
-	if conquered:
-		# #76: a research_lab's whole reward is invisible otherwise - the
-		# research point balance lives in a HUD number the player has no
-		# reason to be watching at the exact moment it changes. Naming the
-		# reward right on the same flash that already announces conquest
-		# is the same "explain it where it happens" idiom BuildController
-		# uses for a refused build.
-		text = "CONQUERED - +1 RESEARCH POINT" \
-			if GameState.planet_definition_id == PLANET_DEFINITIONS.RESEARCH_LAB_ID else "CONQUERED"
-		if not _was_conquered:
-			_flash()
-	else:
-		text = "CAPTURED %d/%d" % [GameState.captured_point_count(planet_id), total]
-	_was_conquered = conquered
-
-
-func _flash() -> void:
-	modulate.a = 0.0
-	var tween: Tween = create_tween()
-	tween.tween_property(self, "modulate:a", 1.0, 1.2)