feat(ui): convert HUD status, stance, interaction prompt to implant theme (D-169)

- HUD: programmatically builds ImplantPanel with health/mode/time rows,
  replaces raw MarginContainer/VBoxContainer/Labels
- Stance indicator: ImplantPanel with color-coded ImplantDataRow,
  replaces custom _draw() with hardcoded bg/text
- Interaction prompt: applies implant theme StyleBox + colors to
  existing PanelContainer layout

Minimap left as-is — its circular frame is a distinct diegetic element,
not rectangular panel chrome.

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

client/ui/stance_indicator.gd

@@ -1,8 +1,7 @@
 extends Control
 
-## D-053: Stance indicator — shows current movement stance on HUD.
+## D-053: Stance indicator — implant-styled badge (D-169).
 ## Sprint/Walk/Careful/Crouch. Color-coded for quick read.
-## Lives on UILayer (z-layer 7).
 
 const STANCE_COLORS := {
 	"Sprint": Color("#d45d5d"),  # Red — fast, loud, dangerous
@@ -11,16 +10,23 @@ const STANCE_COLORS := {
 	"Crouch": Color("#e8c547"),  # Amber — very quiet, slow
 }
 
-const STANCE_DEFAULT_COLOR := Color("#c8d0e0")
-const BG_COLOR := Color(0.05, 0.05, 0.08, 0.5)
-const FONT_SIZE := 13
-const PADDING := Vector2(10, 6)
-
 var _current_stance: String = "Walk"
+var _panel: ImplantPanel
+var _row: ImplantDataRow
 
 
 func _ready() -> void:
 	mouse_filter = Control.MOUSE_FILTER_IGNORE
+	var theme_res := load("res://ui/implant/default_implant.tres") as ImplantTheme
+
+	_panel = ImplantPanel.new()
+	_panel.name = "StancePanel"
+	_panel.theme_resource = theme_res
+	_panel.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	add_child(_panel)
+
+	_row = ImplantDataRow.new("Walk", STANCE_COLORS["Walk"])
+	_panel.add_component(_row)
 
 
 func update_from_state() -> void:
@@ -28,32 +34,8 @@ func update_from_state() -> void:
 	if stance == _current_stance:
 		return
 	_current_stance = stance
-	queue_redraw()
-
-
-func _draw() -> void:
-	var font := ThemeDB.fallback_font
-	var text := _current_stance
-	var text_size := font.get_string_size(text, HORIZONTAL_ALIGNMENT_LEFT, -1, FONT_SIZE)
-	var box_size := text_size + PADDING * 2
-
-	# Background
-	draw_rect(Rect2(Vector2.ZERO, box_size), BG_COLOR)
-
-	# Stance text
-	var color: Color = STANCE_COLORS.get(_current_stance, STANCE_DEFAULT_COLOR)
-	draw_string(
-		font,
-		PADDING + Vector2(0, text_size.y),
-		text,
-		HORIZONTAL_ALIGNMENT_LEFT,
-		-1,
-		FONT_SIZE,
-		color
-	)
-
-
-# -- Public API ---------------------------------------------------------------
+	var color: Color = STANCE_COLORS.get(stance, Color("#c8d0e0"))
+	_row.set_content(stance, color)
 
 
 func get_current_stance() -> String: