fix(ui): atlas review blockers — moon layout, stale grid dims, overlay schema (#128)

1. Moon placement on the orbital diagram divided by a hard-coded 4 — a gas
   giant with five or more moons would overlap satellites and make them
   unclickable. Count moons per parent and distribute them evenly.
2. AtlasViewer._load_markers seeded _grid_w/_grid_h from _tex_w/_tex_h
   before the terrain_reference null check, so opening a body with no
   heightmap after one that had a heightmap left the grid dimensions
   pointing at the previous texture and misplaced markers. Reset texture +
   grid dims to sentinel defaults at the top of _load_heightmap.
3. AtlasMarkerOverlay's three toggleable overlays (production_zones,
   shadow_economy, corp_presence) read markers.production_zones /
   markers.shadow_zones / markers.corp_presence — keys that don't exist in
   D-191 §8's markers schema, so toggling was a silent no-op. Derive them
   from cities[] instead: primary_function ∈ PRODUCTION_FUNCTIONS for
   production, absent Commission presence for shadow bands, Commission
   presence for corp dots. Follow-up ticket will formalise per-overlay
   arrays once the server schema lands.

Addresses PR #128 review blockers 1-3.

client/ui/implant/atlas_marker_overlay.gd

@@ -35,6 +35,11 @@ const COLOR_CORP: Color = Color(0.85, 0.65, 0.20, 0.75)
 const RAIL_DASH_ON: float = 6.0
 const RAIL_DASH_OFF: float = 4.0
 
+const PRODUCTION_FUNCTIONS: Array = [
+	"industrial", "industry", "manufacturing", "extraction", "mining",
+	"refinery", "foundry", "shipyard", "production",
+]
+
 var viewer = null  # AtlasViewer (untyped to avoid cyclic ref)
 
 
@@ -200,24 +205,44 @@ func _draw_population_density(markers: Dictionary) -> void:
 		draw_circle(pos, r, COLOR_POP_HEAT)
 
 
+# Review #3: derive overlays from existing cities[] fields. The original
+# code read production_zones / shadow_zones / corp_presence from keys that
+# are not in the D-191 §8 markers schema, so toggling was a silent no-op.
+# When the server schema lands with explicit zone polygons we can promote
+# these back to dedicated arrays; until then the MVP reads what's there.
 func _draw_production_zones(markers: Dictionary) -> void:
-	for zone: Dictionary in markers.get("production_zones", []):
-		var p: Vector2 = _center_to_canvas(zone.get("center"))
-		var radius: float = float(zone.get("radius", 12.0))
-		draw_circle(p, radius, COLOR_PRODUCTION)
+	for city: Dictionary in markers.get("cities", []):
+		var func_id: String = str(city.get("primary_function", "")).to_lower()
+		if not PRODUCTION_FUNCTIONS.has(func_id):
+			continue
+		var pos: Vector2 = viewer._city_canvas_pos(city)
+		var tier: int = int(city.get("population_tier", 1))
+		var radius: float = 10.0 + float(tier) * 4.0
+		draw_circle(pos, radius, COLOR_PRODUCTION)
 
 
 func _draw_shadow_economy(markers: Dictionary) -> void:
-	for zone: Dictionary in markers.get("shadow_zones", []):
-		var p: Vector2 = _center_to_canvas(zone.get("center"))
-		var radius: float = float(zone.get("radius", 16.0))
-		draw_circle(p, radius, COLOR_SHADOW)
+	# Broad bands around cities outside the Commission's reach. Intentionally
+	# soft + overlapping — D-181 treats shadow zones as "broad bands", not
+	# precise polygons.
+	for city: Dictionary in markers.get("cities", []):
+		var commission: bool = bool(city.get("commission_presence", false))
+		if commission:
+			continue
+		var pos: Vector2 = viewer._city_canvas_pos(city)
+		var tier: int = int(city.get("population_tier", 1))
+		var radius: float = 18.0 + float(tier) * 6.0
+		draw_circle(pos, radius, COLOR_SHADOW)
 
 
 func _draw_corp_presence(markers: Dictionary) -> void:
-	for corp: Dictionary in markers.get("corp_presence", []):
-		var p: Vector2 = _center_to_canvas(corp.get("pos"))
-		draw_rect(Rect2(p - Vector2(3, 3), Vector2(6, 6)), COLOR_CORP)
+	# Tier 1 corp presence — keyed off the Commission-presence flag on cities
+	# until D-191 §8 schema explicitly lists per-corp dots.
+	for city: Dictionary in markers.get("cities", []):
+		if not bool(city.get("commission_presence", false)):
+			continue
+		var pos: Vector2 = viewer._city_canvas_pos(city)
+		draw_rect(Rect2(pos - Vector2(3, 3), Vector2(6, 6)), COLOR_CORP)
 
 
 # =============================================================================

client/ui/implant/atlas_panel.gd

@@ -230,18 +230,34 @@ func _compute_body_positions() -> void:
 				angle = -PI / 2.0 + TAU * float(i) / float(count)
 			_body_positions[b["body_id"]] = center + Vector2(cos(angle), sin(angle)) * ring_r
 
-	# Place moons near their parent body
+	# Place moons near their parent body. Moons per parent count drives the
+	# angular spacing — a hard-coded divisor made the 5th+ moon overlap moon 1
+	# and become unclickable on gas giants with many satellites (review #1).
+	var moons_by_parent: Dictionary = {}
 	for b: Dictionary in _orbital_bodies:
 		var parent_id: Variant = b.get("parent_body_id")
 		if parent_id == null:
 			continue
-		if not _body_positions.has(str(parent_id)):
+		var key: String = str(parent_id)
+		if not moons_by_parent.has(key):
+			moons_by_parent[key] = []
+		moons_by_parent[key].append(b)
+	for parent_key: String in moons_by_parent:
+		if not _body_positions.has(parent_key):
 			continue
-		var parent_pos: Vector2 = _body_positions[str(parent_id)]
-		var moon_idx: int = int(b.get("orbit_index", 1))
-		# Distribute moons around parent at evenly spaced angles
-		var angle: float = -PI / 2.0 + TAU * float(moon_idx - 1) / 4.0
-		_body_positions[b["body_id"]] = parent_pos + Vector2(cos(angle), sin(angle)) * MOON_ORBIT_RADIUS
+		var siblings: Array = moons_by_parent[parent_key]
+		siblings.sort_custom(
+			func(a: Dictionary, b: Dictionary) -> bool:
+				return int(a.get("orbit_index", 0)) < int(b.get("orbit_index", 0))
+		)
+		var parent_pos: Vector2 = _body_positions[parent_key]
+		var count: int = siblings.size()
+		for i: int in range(count):
+			var moon: Dictionary = siblings[i]
+			var angle: float = -PI / 2.0 + TAU * float(i) / float(count)
+			_body_positions[moon["body_id"]] = (
+				parent_pos + Vector2(cos(angle), sin(angle)) * MOON_ORBIT_RADIUS
+			)
 
 	# Place stations near their parent body (offset right + slightly up)
 	for s: Dictionary in _orbital_stations:

client/ui/implant/atlas_viewer.gd

@@ -177,7 +177,13 @@ func get_markers() -> Dictionary:
 
 
 func _load_heightmap() -> void:
+	# Reset to sentinel defaults so a body with no heightmap (or that fails to
+	# load) doesn't inherit the previous body's dimensions — otherwise
+	# grid_to_canvas would project markers using the prior texture size
+	# (review #2).
 	_heightmap_texture = null
+	_tex_w = 1024.0
+	_tex_h = 512.0
 	var ref: Variant = _body.get("terrain_reference")
 	if ref == null or str(ref).is_empty():
 		return
@@ -196,6 +202,8 @@ func _load_heightmap() -> void:
 
 func _load_markers() -> void:
 	_markers = {}
+	# Reset grid dims alongside _tex_* in _load_heightmap so we start from a
+	# known baseline regardless of which body ran previously.
 	_grid_w = _tex_w
 	_grid_h = _tex_h