Map the world view sizing; add RE tooling

- docs/widescreen.md: render-thread frame, cWorldView0 layout and methods,
  view size = zoom * 1024.0/768.0 float constants and all their users,
  ortho projection extents, open questions (activity radius, buffers).
- tools: find-imm (immediate/regex instruction search), rtti (vtables via
  MSVC RTTI), decompile.ps1 + Ghidra scripts for a persistent project;
  ApplyRtti recovers 410 vtables / ~1200 functions Ghidra misses.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tools/README.md

@@ -0,0 +1,25 @@
+# tools
+
+Node tools need `npm install` here once (iced-x86). Paths to sacred.exe are
+passed explicitly.
+
+| Tool | Purpose |
+|---|---|
+| `disasm.mjs <exe> <va> [n]` | disassemble at an address, ignoring Ghidra's function boundaries |
+| `find-imm.mjs <exe> <value...>` | every instruction using an immediate value (e.g. `1024 768`) |
+| `find-imm.mjs <exe> /regex/` | every instruction whose text matches (e.g. `/96AB0h\]/`) |
+| `rtti.mjs <exe> <Class>` | vtables of an MSVC class via RTTI |
+| `decompile.ps1 <addr...>` | decompile from the persistent Ghidra project `ghidra/` |
+
+## Persistent Ghidra project (`ghidra/`, not in git)
+
+Created once (about 7 minutes):
+
+```powershell
+$env:GHIDRA_HEADLESS_MAXMEM = "8G"
+& "$env:GHIDRA_INSTALL_DIR\support\analyzeHeadless.bat" ghidra sacred -import "<Sacred Gold>\sacred.exe"
+& "$env:GHIDRA_INSTALL_DIR\support\analyzeHeadless.bat" ghidra sacred -process sacred.exe -scriptPath tools\ghidra -postScript ApplyRtti.java
+```
+
+`ApplyRtti.java` recovers the MSVC 6 RTTI that Ghidra's own script misses:
+410 vtables, ~1200 extra functions, methods named `Class::vfNN`.