fix(ui): regional atlas — wiki path loading, overlay bar input, header width

Heightmap and markers load from wiki filesystem path via FileAccess
instead of res:// (wiki is outside the Godot project root). Overlay
bar buttons now receive mouse events — viewer skips input processing
when cursor is over UI elements. Header gets explicit minimum width
to prevent vertical text stacking. Shadow economy overlay removed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/ui/implant/apps/atlas/atlas_viewer.gd

@@ -98,12 +98,6 @@ const OVERLAY_DEFS: Array = [
 		"group": "toggle",
 		"tooltip": "Production zones (D-181 observable — requires presence)."
 	},
-	{
-		"id": "shadow_economy",
-		"label": "SHD",
-		"group": "toggle",
-		"tooltip": "Shadow economy zones (D-181 observable)."
-	},
 	{
 		"id": "corp_presence",
 		"label": "CRP",
@@ -269,14 +263,15 @@ func _load_heightmap() -> void:
 	if ref == null or str(ref).is_empty():
 		return
 	var path: String = str(ref)
-	if not path.begins_with("res://"):
-		path = "res://" + path.lstrip("/")
-	if not ResourceLoader.exists(path):
+	if not path.begins_with("/"):
+		var project_root: String = ProjectSettings.globalize_path("res://").get_base_dir().get_base_dir()
+		path = project_root + "/" + path
+	if not FileAccess.file_exists(path):
 		push_warning("AtlasViewer: terrain_reference not found at %s" % path)
 		return
-	var tex: Variant = load(path)
-	if tex is Texture2D:
-		_heightmap_texture = tex
+	var img := Image.load_from_file(path)
+	if img != null:
+		_heightmap_texture = ImageTexture.create_from_image(img)
 		_tex_w = float(_heightmap_texture.get_width())
 		_tex_h = float(_heightmap_texture.get_height())
 
@@ -292,8 +287,9 @@ func _load_markers() -> void:
 	if ref == null or str(ref).is_empty():
 		return
 	var hm_path: String = str(ref)
-	if not hm_path.begins_with("res://"):
-		hm_path = "res://" + hm_path.lstrip("/")
+	if not hm_path.begins_with("/"):
+		var project_root: String = ProjectSettings.globalize_path("res://").get_base_dir().get_base_dir()
+		hm_path = project_root + "/" + hm_path
 	var dir: String = hm_path.get_base_dir()
 	var markers_path: String = dir + "/markers.json"
 
@@ -386,6 +382,7 @@ func _build_screen_header() -> void:
 	# theme-swap invariant violation.
 	_screen_header = ImplantHeader.new()
 	_screen_header.position = Vector2(PANEL_MARGIN, 16.0)
+	_screen_header.custom_minimum_size.x = 320.0
 	_screen_header.mouse_filter = Control.MOUSE_FILTER_IGNORE
 	add_child(_screen_header)
 	if _implant_theme:
@@ -418,6 +415,14 @@ static func _dict_str(d: Dictionary, key: String, fallback: String) -> String:
 # =============================================================================
 
 
+func _is_over_ui(pos: Vector2) -> bool:
+	if _overlay_bar and _overlay_bar.get_global_rect().has_point(pos):
+		return true
+	if _city_panel and _city_panel.visible and _city_panel.get_global_rect().has_point(pos):
+		return true
+	return false
+
+
 func _gui_input(event: InputEvent) -> void:
 	if event is InputEventKey and event.pressed and not event.is_echo():
 		_handle_key(event as InputEventKey)
@@ -426,6 +431,9 @@ func _gui_input(event: InputEvent) -> void:
 	if _heightmap_texture == null:
 		return
 
+	if event is InputEventMouseButton and _is_over_ui((event as InputEventMouseButton).global_position):
+		return
+
 	if event is InputEventMouseButton:
 		var mb := event as InputEventMouseButton
 		if mb.button_index == MOUSE_BUTTON_WHEEL_UP and mb.pressed:
@@ -441,6 +449,8 @@ func _gui_input(event: InputEvent) -> void:
 			else:
 				_dragging = false
 	elif event is InputEventMouseMotion:
+		if _is_over_ui((event as InputEventMouseMotion).global_position):
+			return
 		var mm := event as InputEventMouseMotion
 		if _dragging:
 			_view_offset = _drag_start_offset + (mm.position - _drag_start_mouse)