feat(ui): star map insert module — concentric hop-ring view (#674)

New StarMapRenderer: 301 systems in concentric hop-rings from player
location, sector-colored, click-to-select with info panel, pan/zoom.
Integrated into HUD (hidden by default), insert state propagation
wired in main.gd. Data enriched from systems.db + star-map.json via
tooling/generate-star-map-data.py regeneration script.

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

client/ui/star_map.tscn

@@ -0,0 +1,18 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://ui/star_map.gd" id="1_starmap"]
+
+; #674: Star map insert module — concentric hop-ring view of the Settled Reach gate network.
+; Sector-colored, interactive selection, pan/zoom. Accessible from the insert UI.
+; Data source: res://data/star_map_data.json (enriched from star-map.json + systems.db).
+; Positioned as full-size overlay. Toggle visibility via set_insert_active() or toggle_visible().
+
+[node name="StarMapRenderer" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+mouse_filter = 1
+script = ExtResource("1_starmap")