fix(hero): export smoothing groups; give the facade real collision

UE export hygiene (unreal-export skill checklist) plus a gameplay defect the new
probe caught:

- FBX export now uses mesh_smooth_type="FACE" (was OFF, which is why every import
  logged "No smoothing group information was found"), and the round parts are
  shaded with shade_smooth_by_angle(35 deg) before export, so columns and
  medallions read round instead of faceted.
- SM_HeroFacade had complex-only collision, so capsule sweeps and line traces
  passed through the wall: the player could walk through the hero facade.
  auto_generate_collision was tried and rejected (coarse hulls bulged into the
  street; the QA wall probe went 0/35 -> 2/35). It now uses UseComplexAsSimple,
  saved on the asset, like the terrain.
- New -qaselftest facade occlusion probe: 40 m traces sideways from the road
  centre at walking height, required only where a building is staged (explicit X
  spans mirroring ue_build_demo_map). Result 0/9 -> PASS, alongside transect
  0 holes and wall probe 0/35.

Docs: release-checks records the probe and both collision attempts; Tools/README
lists the new phase; MEMORY records the smoothing/collision lessons.

Game/GigLine/Source/GigLine/GigLineCharacter.cpp

@@ -416,6 +416,81 @@ void AGigLineCharacter::StartQASelfTest()
 					TEXT("GigLine QA: wall probe %d/%d traces with blocking hit inside 21 m -> %s"),
 					Walls, WallSamples,
 					Walls == 0 ? TEXT("PASS") : TEXT("FAIL"));
+
+				// Facade occlusion probe: walkable street is only half the story —
+				// the player must also NOT be able to walk through the buildings.
+				// From the road centre, fire 40 m sideways at walking height toward
+				// each frontage and require a blocking hit. A miss means the
+				// building has no collision (or only non-blocking collision) and the
+				// player would pass through the wall.
+				// Expect a wall only where the map actually stages a building.
+				// Spans below mirror the actors placed by Tools/ue_build_demo_map.py
+				// (frontage + hero) and the two north buildings; update them if
+				// that list changes. Gaps between buildings are legitimate misses.
+				struct FSpan { float Min, Max; };
+				static const FSpan SouthSpans[] = {
+					{-24276.f, -17700.f}, // 6922
+					{-17749.f, -14591.f}, // 6902
+					{-14638.f, -12034.f}, // 6840 hero
+					{-12082.f, -8210.f},  // 6838 El Capitan Theatre
+					{-7854.f, -7252.f},   // 6822 Budget
+					{-6608.f, -3307.f},   // 6806-6820
+					{-3320.f, -1437.f},   // 6800 Lee Drug
+				};
+				static const FSpan NorthSpans[] = {
+					{-27071.f, -22799.f}, // Madame Tussaud's
+					{-22889.f, -18442.f}, // TCL Chinese Theatre
+				};
+				auto InSpans = [](const FSpan* Spans, int32 Count, float X)
+				{
+					for (int32 i = 0; i < Count; ++i)
+					{
+						if (X >= Spans[i].Min && X <= Spans[i].Max) { return true; }
+					}
+					return false;
+				};
+				int32 Facades = 0, FacadeSamples = 0;
+				for (float X0 = -19000.0f; X0 <= -3000.0f; X0 += 2000.0f)
+				{
+					for (float Dir : {1.0f, -1.0f}) // +Y south frontage, -Y north side
+					{
+						const bool bExpectWall = (Dir > 0.0f)
+							? InSpans(SouthSpans, UE_ARRAY_COUNT(SouthSpans), X0)
+							: InSpans(NorthSpans, UE_ARRAY_COUNT(NorthSpans), X0);
+						if (!bExpectWall)
+						{
+							continue;
+						}
+						FHitResult GroundHit2;
+						FCollisionQueryParams GQ2(TEXT("GigLineFacadeGround"), false, this);
+						if (!W->LineTraceSingleByChannel(GroundHit2,
+							FVector(X0, 0.0f, 3000.f), FVector(X0, 0.0f, -1000.f),
+							ECC_Visibility, GQ2))
+						{
+							continue;
+						}
+						const float ProbeZ2 = GroundHit2.ImpactPoint.Z + 160.f;
+						FHitResult Hit2;
+						FCollisionQueryParams Q2(TEXT("GigLineFacadeProbe"), false, this);
+						const bool bHit2 = W->LineTraceSingleByChannel(Hit2,
+							FVector(X0, 0.0f, ProbeZ2),
+							FVector(X0, Dir * 4000.f, ProbeZ2),
+							ECC_Visibility, Q2);
+						++FacadeSamples;
+						const bool bBlocking = bHit2 && Hit2.GetActor() != nullptr;
+						if (!bBlocking)
+						{
+							++Facades;
+							UE_LOG(LogTemp, Log,
+								TEXT("GigLine QA: facade probe miss at X %.0f dir %.0f (no blocking hit in 40 m)"),
+								X0, Dir);
+						}
+					}
+				}
+				UE_LOG(LogTemp, Log,
+					TEXT("GigLine QA: facade probe %d/%d directions without a blocking wall -> %s"),
+					Facades, FacadeSamples,
+					Facades == 0 ? TEXT("PASS") : TEXT("FAIL"));
 			}
 
 			// 7.0: verdict, then stop ticking.