refactor(tools): group the sixty scripts by what they talk to

One directory with sixty scripts stopped being navigable, and the grouping is also the sandbox boundary:

  Tools/unreal/    commandlets and the two map builders, with ue_common.py and ue_placement.py as the
                   shared imports (they need the engine)
  Tools/blender/   builders, exporters, the FBX preset, the MPFB character pipeline, blender_screenshots
                   (they need the Blender Flatpak)
  Tools/review/    the visual loop: render_screenshots.sh, judge_screenshot.py, hero_compare.py,
                   build_comparison_md.py, e2e_asset_check.py, hero_iterate.sh, visual_loop.py,
                   visual_targets.json
  Tools/gen/       image and texture generation: the ComfyUI driver, deterministic texture writers,
                   reference fetching
  Tools/input/     OS-level input injection
  root             _common.py, check-lfs.sh, addon_compat_probe.py, sibling_asset_audit.py, tests/

Every moved script now resolves the repository root as ../.. and puts the tools root plus its siblings on
sys.path, so 'import ue_common' still works from unreal/. The test suite bootstrap does the same for the five
folders. render_screenshots.sh takes the folder as a third argument to run_cmdlet, and the e2e driver,
hero_iterate.sh and the comparison generator were repointed.

51 README rows now link to their new location, the README gains a Layout section naming each folder's
sandbox, and the architecture notes and Blender README follow the moves.

Verified: 108 tests pass, prettier is clean, judge_screenshot.py and hero_compare.py run from their new
homes, and the e2e run was aborted mid-way (it had been rebuilding an empty DemoMap for 15 minutes) and is
being rerun against the new layout.

Tools/tests/test_block_height_report.py

@@ -4,6 +4,15 @@ The Geo tools live outside `Tools/`, so the test adds `Geo/tools` to `sys.path`
 before importing the module by name.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import unittest

Tools/tests/test_character_match.py

@@ -1,5 +1,14 @@
 """Tests for the pure parts of Tools/character_match.py."""
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import unittest

Tools/tests/test_comfyui_texture.py

@@ -1,5 +1,14 @@
 """Graph shape for the documented texture workflows (no ComfyUI process involved)."""
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import unittest
 
 from comfyui_generate import TEXTURE_PROFILES, texture_workflow

Tools/tests/test_facade_detail_concepts.py

@@ -4,6 +4,15 @@ No network calls: the OpenRouter request and the image bytes are represented as
 the small structures the API uses. Generation itself is manual and paid.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import base64
 import json
 import os

Tools/tests/test_fbx_export_preset.py

@@ -5,6 +5,15 @@ The preset module keeps its argument set in plain dicts and builds it in
 Blender. Only `export_static`/`export_character` import `bpy`.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import unittest

Tools/tests/test_input_emulation.py

@@ -5,6 +5,15 @@ covered here; the end-to-end injection is verified by running the tool (see
 Docs/release-checks.md and MEMORY.md).
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import unittest
 
 import input_emulation as ie

Tools/tests/test_judge_combine.py

@@ -1,5 +1,14 @@
 """Tests for the multi-model reconciliation in judge_screenshot.combine()."""
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import unittest
 
 from judge_screenshot import combine

Tools/tests/test_mapbox_buildings.py

@@ -5,6 +5,15 @@ the API returns, and only the selection/comparison/formatting helpers are
 exercised. The live call is verified by running the tool.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import json
 import os
 import sys

Tools/tests/test_retail_frontage.py

@@ -4,6 +4,15 @@ The builder itself needs Blender; `bay_centres` does not, so the bay rhythm the
 façade depends on is checkable without starting Blender or Unreal.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import unittest
 
 from Tools._common import bay_centres

Tools/tests/test_shadow_gap.py

@@ -1,5 +1,14 @@
 """Tests for the pure parts of Tools/shadow_gap.py."""
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import unittest

Tools/tests/test_ue_common.py

@@ -4,6 +4,15 @@ Pure stdlib: these helpers exist to turn two silent failures into loud ones, so
 they are tested without starting Unreal.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import stat
 import sys

Tools/tests/test_ue_placement.py

@@ -6,6 +6,15 @@ Running the importer moved the hero 13 m east and onto the north side of the
 boulevard, and nothing complained because a displaced building still renders.
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import unittest
@@ -70,14 +79,14 @@ class SingleSourceOfTruthTest(unittest.TestCase):
     """The import script and the demo builder must not carry their own literals."""
 
     def test_import_script_uses_the_shared_constant(self):
-        src = open(os.path.join(ROOT, "Tools", "ue_hero_facade_import.py"),
+        src = open(os.path.join(ROOT, "Tools", "unreal", "ue_hero_facade_import.py"),
                    encoding="utf-8").read()
         self.assertIn("ue_placement.HERO_LOCATION_CM", src)
         self.assertNotIn("(-12024.5, -1450.0, 0.0)", src,
                          "the stale pre-0.1.0 hero position must not come back")
 
     def test_demo_builder_uses_the_shared_constant(self):
-        src = open(os.path.join(ROOT, "Tools", "ue_build_demo_map.py"),
+        src = open(os.path.join(ROOT, "Tools", "unreal", "ue_build_demo_map.py"),
                    encoding="utf-8").read()
         self.assertIn("ue_placement.HERO_LOCATION_CM", src)
 

Tools/tests/test_visual_loop.py

@@ -5,6 +5,15 @@ numbers can be reasoned about directly (a mid-grey flat frame has near-zero edge
 density and contrast; a checkerboard has a lot of both).
 """
 
+import os
+import sys
+
+_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, _TOOLS)
+for _sub in ("review", "gen", "unreal", "blender", "input"):
+    sys.path.insert(0, os.path.join(_TOOLS, _sub))
+
+
 import os
 import sys
 import tempfile