feat(ui): wire atlas Layer-1 request/re-poll to generation overlays (#960)

show_body() now requests the body's Layer-1 cascade output via
SimBridge.request_atlas_layers(); the response feeds set_generation_layer1().
The proxy returns Pending on a cache miss and generates in the background
(D-225), so the viewer re-requests every 0.5s (20-retry ceiling) until Ready,
guarding against stale responses by body_id. Serverless/test mode is a no-op
(overlays stay empty). Connected in _ready, torn down in _exit_tree.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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

@@ -31,6 +31,11 @@ const MIN_ZOOM: float = 0.5
 const MAX_ZOOM: float = 8.0
 const ZOOM_STEP: float = 1.15
 
+# #960: Layer-1 proxy re-poll. The proxy returns Pending on a cache miss and
+# generates in the background (D-225); the client re-requests until Ready.
+const GEN_RETRY_DELAY: float = 0.5
+const GEN_MAX_RETRIES: int = 20  # ~10s ceiling before giving up
+
 const PANEL_WIDTH: float = 320.0
 const PANEL_MARGIN: float = 16.0
 
@@ -145,6 +150,8 @@ var _implant_theme = null
 var _heightmap_texture: Texture2D = null
 var _markers: Dictionary = {}
 var _generation_layer1: Variant = null  # #960: Layer1Output from the proxy (D-225)
+var _gen_pending: bool = false  # #960: awaiting a Layer1 response (re-polls on Pending)
+var _gen_retries: int = 0
 var _grid_w: float = 512.0
 var _grid_h: float = 256.0
 var _tex_w: float = 1024.0
@@ -208,6 +215,14 @@ func _ready() -> void:
 	_build_empty_notice()
 	_build_overlay_bar()
 
+	# #960: receive proxied Layer-1 generation output (D-225).
+	SimBridge.atlas_layers_received.connect(_on_atlas_layers_received)
+
+
+func _exit_tree() -> void:
+	if SimBridge.atlas_layers_received.is_connected(_on_atlas_layers_received):
+		SimBridge.atlas_layers_received.disconnect(_on_atlas_layers_received)
+
 
 ## Called by RegionalScreen.enter() when entering the viewer for a specific body.
 func show_body(body: Dictionary, system: Dictionary) -> void:
@@ -221,6 +236,10 @@ func show_body(body: Dictionary, system: Dictionary) -> void:
 	_refresh_screen_header()
 	_city_panel.visible = false
 	_empty_notice.visible = (_heightmap_texture == null)
+	_generation_layer1 = null
+	_gen_pending = false
+	_gen_retries = 0
+	_request_generation_layers()
 	grab_focus()
 	queue_redraw()
 	_overlay_node.queue_redraw()
@@ -265,6 +284,49 @@ func get_generation_layer1() -> Variant:
 	return _generation_layer1
 
 
+## #960: request the body's Layer-1 cascade output from the server proxy.
+## No-op in test mode (SimBridge has no server connection) — the overlays
+## simply stay empty, which is the correct serverless behavior.
+func _request_generation_layers() -> void:
+	var body_id: String = _dict_str(_body, "body_id", "")
+	if body_id.is_empty():
+		return
+	_gen_pending = true
+	SimBridge.request_atlas_layers(body_id)
+
+
+## #960: handle a Layer-1 response. Ignores responses for a stale body (the
+## user navigated away). On Pending the proxy is still generating, so we
+## re-request after a short delay until Ready or the retry ceiling.
+func _on_atlas_layers_received(response: Dictionary) -> void:
+	var body_id: String = _dict_str(_body, "body_id", "")
+	if str(response.get("body_id", "")) != body_id:
+		return
+	match str(response.get("status", "")):
+		"Ready":
+			_gen_pending = false
+			_gen_retries = 0
+			set_generation_layer1(response.get("layer1"))
+		"Pending":
+			if _gen_retries < GEN_MAX_RETRIES:
+				_gen_retries += 1
+				_schedule_gen_retry(body_id)
+			else:
+				_gen_pending = false  # gave up — overlays stay empty
+		_:
+			_gen_pending = false  # NotFound / Error — nothing to draw
+
+
+func _schedule_gen_retry(body_id: String) -> void:
+	var timer := get_tree().create_timer(GEN_RETRY_DELAY)
+	timer.timeout.connect(
+		func() -> void:
+			# Re-request only if still on the same body and still waiting.
+			if _gen_pending and _dict_str(_body, "body_id", "") == body_id:
+				SimBridge.request_atlas_layers(body_id)
+	)
+
+
 func get_hovered_city() -> Dictionary:
 	return _hovered_city