fix issue where construction sites could be placed outside of game world and add tests

src/test/BlueprintTest.cpp

@@ -589,6 +589,49 @@ TEST_CASE("Blueprint placement: insufficient blocks returns kInvalidBuildingId a
     REQUIRE(sim.buildingBlocksStock() == blocksBeforeAttempt);
 }
 
+TEST_CASE("Simulation: tryPlaceBuilding rejects terrain-invalid placement and charges nothing",
+          "[blueprint]")
+{
+    Simulation sim(loadConfig());
+    const int startBlocks = sim.buildingBlocksStock();
+
+    // A miner is all-asteroid; placing it in space (x >= 0) violates the terrain
+    // rule, so it must be rejected without consuming building blocks.
+    const BuildingId id =
+        sim.tryPlaceBuilding(BuildingType::Miner, QPoint(0, 0), Rotation::East);
+
+    REQUIRE(id == kInvalidBuildingId);
+    REQUIRE(sim.buildingBlocksStock() == startBlocks);
+    REQUIRE(sim.buildings().allSites().empty());
+}
+
+TEST_CASE("Simulation: tryPlaceBuilding accepts a valid asteroid spot, occupies tiles, charges cost",
+          "[blueprint]")
+{
+    Simulation sim(loadConfig());
+
+    int minerCost = 0;
+    for (const BuildingDef& def : sim.config().buildings.buildings)
+    {
+        if (def.type == BuildingType::Miner) { minerCost = def.cost; break; }
+    }
+    REQUIRE(minerCost > 0);
+    const int startBlocks = sim.buildingBlocksStock();
+
+    // Miner mask ["AA","A>"] East at (-3,0) → all-asteroid body at
+    // (-3,0),(-2,0),(-3,1); a valid spot.
+    const BuildingId id =
+        sim.tryPlaceBuilding(BuildingType::Miner, QPoint(-3, 0), Rotation::East);
+
+    REQUIRE(id != kInvalidBuildingId);
+    REQUIRE(sim.buildingBlocksStock() == startBlocks - minerCost);
+    REQUIRE(sim.buildings().isTileOccupied(QPoint(-3, 0)));
+    REQUIRE(sim.buildings().isTileOccupied(QPoint(-2, 0)));
+    REQUIRE(sim.buildings().isTileOccupied(QPoint(-3, 1)));
+    // The output-port tile (1,1)+anchor = (-2,1) is not a body cell.
+    REQUIRE_FALSE(sim.buildings().isTileOccupied(QPoint(-2, 1)));
+}
+
 // ---------------------------------------------------------------------------
 // Recipe / schematic capture and re-application
 // ---------------------------------------------------------------------------