fix(ui): implant panel width constraint and text wrapping

Panel now clips content and constrains children to its width.
Components set autowrap and SIZE_FLAGS_FILL so text wraps within
the panel instead of overflowing. Bold markdown markers stripped
in ImplantTextBlock constructor.

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

client/ui/star_map.gd

@@ -113,6 +113,7 @@ func _ready() -> void:
 	_info_panel.name = "InfoPanel"
 	_info_panel.theme_resource = _implant_theme
 	_info_panel.custom_minimum_size.x = POPUP_WIDTH
+	_info_panel.size.x = POPUP_WIDTH
 	_info_panel.visible = false
 	_info_panel.mouse_filter = Control.MOUSE_FILTER_IGNORE
 	add_child(_info_panel)