feat: hero facade blockout for 6840 Hollywood Blvd

Tools/hero_facade_build.py builds the north elevation parametrically and writes
a JSON report naming the evidence behind every part: the 25.75 m frontage and
14.5 m height are measured, the 4.96 m column bay comes from the sibling notes
and matches that frontage, the three portal flights follow the photographs (five
risers, overturning the inherited eight-step, 12 m wide claim), and the rest is
labelled assumption.

Tools/ue_hero_facade_import.py imports it with the ue_metric_v1 preset
(2604 x 1257 x 1450 cm, 1892 tris, 4 materials) and places it on the measured
building line of /Game/Hollywood/DemoMap.

Two new review shots at review-04 and review-05, both pending approval. Camera
placement cost four renders: the first two sat inside the facade body, and the
frontage faces Unreal -Y, so a camera has to stand at Y < -1450 cm, not north of
the building line in project terms.

Tools/ue_hero_facade_import.py

@@ -0,0 +1,106 @@
+# Imports the hero façade FBX into Unreal with the named preset `ue_metric_v1`
+# and places it at the measured site position.
+#
+#   <engine>/Engine/Binaries/Linux/UnrealEditor-Cmd <uproject> -run=pythonscript \
+#     -script=<repo>/Tools/ue_hero_facade_import.py -nullrhi -unattended -nopause -stdout
+#
+# Placement follows Geo/manifests/local-origin.md and the blockout frame:
+#   project X = UTM easting - 376515.389 (east +)
+#   project Y = -(UTM northing - 3774224.083)  in Unreal, because the FBX preset
+#   maps Blender +Y (north) to Unreal -Y and Blender +X to Unreal +X. The building
+#   line of the hero block sits at Unreal Y = -1450 cm (14.5 m south of the road
+#   centreline, from the street profile), and the hero's east edge at
+#   X = -12024.5 cm (projected control point in local-origin.md).
+
+import unreal
+
+FBX = "/tmp/gigline/hero-facade.fbx"
+DEST = "/Game/Hollywood/ElCapitan"
+ACTOR_LABEL = "Hero_Facade"
+LEVEL = "/Game/Hollywood/DemoMap"
+
+# Unreal centimetres: south-east corner of the façade, on the building line.
+PLACEMENT_CM = (-12024.5, -1450.0, 0.0)
+
+RESULT = "/tmp/gigline/hero-facade-import.txt"
+lines = []
+
+
+def log(msg):
+    lines.append(str(msg))
+
+
+def import_fbx():
+    task = unreal.AssetImportTask()
+    task.filename = FBX
+    task.destination_path = DEST
+    task.destination_name = "SM_HeroFacade"
+    task.automated = True
+    task.save = True
+    task.replace_existing = True
+
+    ui = unreal.FbxImportUI()
+    ui.import_mesh = True
+    ui.import_materials = True
+    ui.import_textures = False
+    ui.import_as_skeletal = False
+    smd = ui.static_mesh_import_data
+    smd.import_uniform_scale = 1.0
+    smd.combine_meshes = True
+    smd.convert_scene_unit = False
+    smd.force_front_x_axis = False
+    smd.normal_import_method = unreal.FBXNormalImportMethod.FBXNIM_IMPORT_NORMALS
+    task.options = ui
+
+    unreal.AssetToolsHelpers.get_asset_tools().import_asset_tasks([task])
+    unreal.EditorLoadingAndSavingUtils.save_dirty_packages(True, True)
+
+
+def measure_and_place():
+    asset = unreal.EditorAssetLibrary.load_asset(f"{DEST}/SM_HeroFacade")
+    if asset is None:
+        log(f"MISSING {DEST}/SM_HeroFacade")
+        return
+    box = asset.get_bounding_box()
+    mn, mx = box.min, box.max
+    log(f"SM_HeroFacade bounds cm: size=({mx.x - mn.x:.1f}, {mx.y - mn.y:.1f}, {mx.z - mn.z:.1f}) "
+        f"min=({mn.x:.1f}, {mn.y:.1f}, {mn.z:.1f})")
+    # StaticMaterial is a struct wrapper: the material is its material_interface.
+    names = []
+    for sm in asset.get_editor_property("static_materials"):
+        mat = sm.get_editor_property("material_interface")
+        names.append(mat.get_name() if mat else "None")
+    log(f"materials: {names}")
+
+    # Place on the demo map if it exists; otherwise create it from the empty level.
+    if unreal.EditorAssetLibrary.does_asset_exist(LEVEL):
+        unreal.EditorLevelLibrary.load_level(LEVEL)
+    else:
+        if not unreal.EditorLevelLibrary.new_level(LEVEL):
+            log(f"could not create {LEVEL}")
+            return
+    for actor in unreal.EditorLevelLibrary.get_all_level_actors():
+        if actor.get_actor_label() == ACTOR_LABEL:
+            unreal.EditorLevelLibrary.destroy_actor(actor)
+    actor = unreal.EditorLevelLibrary.spawn_actor_from_class(
+        unreal.StaticMeshActor, unreal.Vector(*PLACEMENT_CM))
+    actor.set_actor_label(ACTOR_LABEL)
+    comp = actor.static_mesh_component
+    comp.set_static_mesh(asset)
+    comp.set_mobility(unreal.ComponentMobility.STATIC)
+    log(f"placed {ACTOR_LABEL} at {PLACEMENT_CM} (cm) on {LEVEL}")
+    saved = unreal.EditorLoadingAndSavingUtils.save_map(
+        unreal.EditorLevelLibrary.get_editor_world(), LEVEL)
+    log(f"save_map {LEVEL}: {saved}")
+
+
+try:
+    import_fbx()
+    measure_and_place()
+except Exception as exc:  # noqa: BLE001
+    import traceback
+    log(f"FAILED: {type(exc).__name__}: {exc}")
+    log(traceback.format_exc())
+
+with open(RESULT, "w") as handle:
+    handle.write("\n".join(lines) + "\n")