docs: bring every document in line with the current build

README rewritten around the actual state (walkable DemoMap, blockout facades,
planned patches); Tools/README now lists all seventeen tools by role; build.md
gains the content pipeline table and the two enforced rules (one unit conversion,
collision decided at import). Setup gains a content-pipeline row, the toolchain
state notes the demo level exercises the engine path, release checks record the
Blender pre-check that backs traversal, PLAN points at ROADMAP/MEMORY/Screenshots,
and THIRD_PARTY_NOTICES gains rows for the hero facade and the candidate props.

Also fixed the last stale reference to Geo/scripts in MEMORY.md - a sweep found
old paths in six documents after the tool move, which the memory entry now warns
about.

PLAN.md

@@ -47,6 +47,8 @@ Target workstation: Bazzite Linux, Ryzen 7 7700X, 64 GB RAM, RTX 5070 Ti 16 GB.
 
 ### Repository
 
+Progress lives in `ROADMAP.md`; session findings live in `MEMORY.md`; rendered review captures and their approval state live in `Screenshots/`.
+
 - `Game/` — Unreal project, configuration, source, game-ready content.
 - `Art/` — editable Blender files and original textures.
 - `Geo/` — source manifests, permitted geographic data, processing scripts.