feat(simulation): atlas proxy layers + data-delivery endpoints (T-960, T-949)

T-960: RoadGraphLayer (L2 edges/junctions, MaintenanceAuthority, rail flag, named routes) + SettlementLayer (name/position/size-class/is_capital/is_port from T-955 placements) as new Option fields on AtlasLayerResponse — T-1046 precedent; layer_proxy doc comment corrected (cascade runs through RoadGraph, client up_to ignored). T-949: new StarMapRequest/StarMapResponse (raw JSON passthrough of the star_map_data.json bake) + CityNamesRequest/CityNamesResponse (atlas_city_names via CityContextReader) with defense-in-depth Sol exclusion (GJ-0 system id OR settlement_wave='origin', D-236). Inbound demux extended with mandatory boolean discriminator fields (serde ignores unknown fields — optional-shape sniffing would be ambiguous); AtlasLayerRequest unchanged. SimBridge trait +2 methods, implemented on TcpBridge + LocalBridge. CityPlacement/CityRecord gained name/population/is_capital (BodyWorldState cache-hit path stays DB-free). ~30 new unit tests incl. demux disambiguation + Sol branches; gen_fixtures extended for road/settlement samples.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

server/tests/bridge_tcp.rs

@@ -338,7 +338,8 @@ fn single_tick_drains_all_ready_inbound_frames() {
     use settled_reach_server::atlas::cascade::CascadeLayer;
     use settled_reach_server::atlas::layer_proxy::AtlasLayerRequest;
     use settled_reach_server::bridge::{
-        receive_bridge_inputs, AtlasRequestBuffer, BridgeResource, HandshakeState, ServerRunning,
+        receive_bridge_inputs, AtlasRequestBuffer, BridgeResource, CityNamesRequestBuffer,
+        HandshakeState, ServerRunning, StarMapRequestBuffer,
     };
     use settled_reach_server::simulation::input::InputQueue;
 
@@ -379,6 +380,8 @@ fn single_tick_drains_all_ready_inbound_frames() {
     world.insert_resource(HandshakeState::Complete);
     world.init_resource::<SimErrorBuffer>();
     world.init_resource::<AtlasRequestBuffer>();
+    world.init_resource::<StarMapRequestBuffer>();
+    world.init_resource::<CityNamesRequestBuffer>();
 
     world
         .run_system_once(receive_bridge_inputs)

server/tests/gen_fixtures.rs

@@ -3,10 +3,14 @@
 
 use settled_reach_server::atlas::body_world_state::{DrainageBasin, RiverNetwork};
 use settled_reach_server::atlas::layer1::Layer1Output;
-use settled_reach_server::atlas::layer_proxy::{AtlasLayerResponse, AtlasLayerStatus};
+use settled_reach_server::atlas::layer_proxy::{
+    AtlasLayerResponse, AtlasLayerStatus, RoadGraphEdge, RoadGraphLayer, RoadGraphNode,
+    SettlementEntry, SettlementLayer, SettlementSizeClass,
+};
+use settled_reach_server::atlas::road_graph::RoadNodeKind;
 use settled_reach_server::bridge::types::*;
 use settled_reach_server::simulation::generator::{
-    AttractorType, GeographicAttractor, SubBiomeVariant,
+    AttractorType, GeographicAttractor, MaintenanceAuthority, SubBiomeVariant,
 };
 use settled_reach_server::simulation::poi::PoiCategory;
 use settled_reach_server::simulation::time::{DayPhase, TickRate};
@@ -568,11 +572,58 @@ fn generate_atlas_layer_response_fixtures() {
         grid_h: 256,
         district_basin_dirs: std::collections::BTreeMap::new(),
     };
+    // T-960 §1/§2: a small populated RoadGraphLayer + SettlementLayer, one
+    // settlement (a capital) connected to one waypoint-free short edge.
+    let road_graph = RoadGraphLayer {
+        nodes: vec![
+            RoadGraphNode {
+                position: (12, 58),
+                kind: RoadNodeKind::Settlement,
+                city_id: Some(1),
+            },
+            RoadGraphNode {
+                position: (20, 70),
+                kind: RoadNodeKind::Settlement,
+                city_id: Some(2),
+            },
+        ],
+        edges: vec![RoadGraphEdge {
+            from: 0,
+            to: 1,
+            path: vec![(12, 58), (16, 64), (20, 70)],
+            maintenance: MaintenanceAuthority::Administrative,
+            is_rail: false,
+            named_route_id: None,
+        }],
+    };
+    let settlements = SettlementLayer {
+        settlements: vec![
+            SettlementEntry {
+                city_id: 1,
+                name: "Port Aldren".into(),
+                position: (12, 58),
+                size_class: SettlementSizeClass::Major,
+                is_capital: true,
+                is_port: true,
+            },
+            SettlementEntry {
+                city_id: 2,
+                name: "Farmstead Rell".into(),
+                position: (20, 70),
+                size_class: SettlementSizeClass::Minor,
+                is_capital: false,
+                is_port: false,
+            },
+        ],
+    };
+
     let ready = AtlasLayerResponse {
         body_id: "GJ1c".into(),
         status: AtlasLayerStatus::Ready,
         layer1: Some(layer1),
         district_grid: None,
+        road_graph: Some(road_graph),
+        settlements: Some(settlements),
     };
     write_fixture(
         "atlas_response_ready",
@@ -584,6 +635,8 @@ fn generate_atlas_layer_response_fixtures() {
         status: AtlasLayerStatus::Pending,
         layer1: None,
         district_grid: None,
+        road_graph: None,
+        settlements: None,
     };
     write_fixture(
         "atlas_response_pending",
@@ -595,6 +648,8 @@ fn generate_atlas_layer_response_fixtures() {
         status: AtlasLayerStatus::NotFound,
         layer1: None,
         district_grid: None,
+        road_graph: None,
+        settlements: None,
     };
     write_fixture(
         "atlas_response_not_found",