refactor(ui): convert HUD status + interaction prompt to implant (#786, #788)

HUD: merge TimeDisplay into ImplantPanel (time/health/perception in one
panel), remove dead tscn nodes, move HUD to InsertOverlay for D-051 bloom.
Interaction prompt: convert from PanelContainer+StyleBoxFlat to Control
with ImplantPanel+ImplantDataRow, fix panel height for 42px minimum.
Tests updated for new scene structure and public API.

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

client/tests/test_interaction_prompt.gd

@@ -222,15 +222,9 @@ func test_interact_with_data_encodes_as_data_variant() -> void:
 
 # -- Helpers --
 
-func _make_prompt() -> PanelContainer:
+func _make_prompt() -> Control:
 	var PromptScript = load("res://ui/interaction_prompt.gd")
-	var panel = PanelContainer.new()
-	panel.set_script(PromptScript)
-	var margin = MarginContainer.new()
-	margin.name = "MarginContainer"
-	panel.add_child(margin)
-	var label = Label.new()
-	label.name = "PromptLabel"
-	margin.add_child(label)
-	add_child(panel)
-	return panel
+	var ctrl = Control.new()
+	ctrl.set_script(PromptScript)
+	add_child(ctrl)  # triggers _ready() which creates ImplantPanel + ImplantDataRow
+	return ctrl

client/tests/test_time_display_sprint17.gd

@@ -5,15 +5,15 @@
 ##   D-031 (game time: 10 ticks = 1 game-minute, 1440 min/day, HH:MM display)
 ##   D-051 (diegetic insert display)
 ##
-## Implementation: client/ui/time_display.gd — draw-based Control at InsertOverlay/TimeDisplay.
+## Implementation: client/ui/time_display.gd — draw-based Control (removed from main scene #786;
+## time display merged into HUD ImplantPanel at UILayer/HUD, see test_hud_* tests below).
 ## Format function: Constants.format_game_time(time_of_day: int) -> String (extracted for
-## testability from time_display.gd:46 inline Constants.format_game_time(tod)).
+## testability from time_display.gd).
 ##
 ## Private state access: Tests read _time_str, _phase_str, _day_str, _has_data directly
 ## because time_display.gd is draw-based (no Label nodes to inspect). This is an accepted
 ## test pattern for draw-based UI — the private vars ARE the rendered output contract.
-## If the rendering approach changes (e.g. to Label nodes), these tests should switch to
-## reading Label.text via public node paths instead.
+## Scene integration tests now check UILayer/HUD.get_time_text() instead.
 class_name TestTimeDisplaySprint17
 extends GdUnitTestSuite
 
@@ -273,18 +273,18 @@ func test_sim_bridge_day_phase_is_valid() -> void:
 
 
 # -------------------------------------------------------------------------
-# Scene: InsertClock node at InsertOverlay/TimeDisplay
+# Scene: HUD panel at UILayer/HUD (time row merged in, TimeDisplay removed #786)
 # -------------------------------------------------------------------------
 
-func test_insert_clock_exists_in_ui_layer() -> void:
+func test_hud_panel_exists_in_ui_layer() -> void:
 	var scene := MAIN_SCENE
 	var instance = scene.instantiate()
 	auto_free(instance)
 	add_child(instance)
 
-	assert_that(instance.get_node_or_null("InsertOverlay/TimeDisplay")).is_not_null()
+	assert_that(instance.get_node_or_null("UILayer/HUD")).is_not_null()
 
-func test_insert_clock_time_str_updates_after_process() -> void:
+func test_hud_time_row_updates_after_process() -> void:
 	var scene := MAIN_SCENE
 	var instance = scene.instantiate()
 	auto_free(instance)
@@ -296,9 +296,9 @@ func test_insert_clock_time_str_updates_after_process() -> void:
 	})
 	instance._process(0.016)
 
-	var clock = instance.get_node_or_null("InsertOverlay/TimeDisplay")
-	assert_that(clock).is_not_null()
-	assert_that(clock._time_str).is_equal("12:00")
+	var hud = instance.get_node_or_null("UILayer/HUD")
+	assert_that(hud).is_not_null()
+	assert_that(hud.get_time_text()).is_equal("12:00 · Afternoon · D1")
 
 
 # -------------------------------------------------------------------------