docs(port-plan): close migration prerequisite gaps

.agents/skills/metin2-40250-parity-audit/SKILL.md

@@ -27,13 +27,13 @@ The 40250 source is the specification. Do not design behavior; transcribe it. Co
 ## Code layout: mirror 40250
 
 The logic layer has the 40250 structure, not a new architecture. Route, batch order and
-prerequisites (2A base, 2R pack inventory, 2V vertical slice) are in `docs/PORT-PLAN.md`. `port_map.py` assigns every unit
+prerequisites (2A base, 2R pack inventory, 2V0-2V3 vertical slices) are in `docs/PORT-PLAN.md`. `port_map.py` assigns every unit
 one of three layers:
 
 | Layer | 40250 units | How to port | Where |
 | --- | --- | --- | --- |
 | `logic` | `UserInterface/`, `GameLib/`, `EterLib` net/timer/text parsing, `EterPack`, `EterLocale` (everything not listed below) | Copy C++ -> C++. Same file name, class name, method names, member names and statement order; one reference file = one implementation file | `extension/src/port/<Lib>/<File>.{h,cpp}` |
-| `python` | `Client/Eternexus/root/*.py`, `uiscript/`, `UserInterface/*Module.cpp`, `EterPythonLib/`, `ScriptLib/` | Decided: embedded CPython 2.7.18 runs the scripts unchanged (`docs/PYTHON-EMBED-EVAL.md`, batch 2P); port only the C++ side. Never translate the scripts. Script functions get `RUN_AS_IS` (after the 2A re-baseline), never `N_A`. Reference is 40250 `Eternexus/root`, **not** `assets/root` | `extension/src/port/<Lib>/` (bindings), scripts from pack |
+| `python` | `Client/Eternexus/root/*.py`, `uiscript/`, `UserInterface/*Module.cpp`, `EterPythonLib/`, `ScriptLib/` | Decided: embedded CPython 2.7.18 runs the scripts unchanged (`docs/PYTHON-EMBED-EVAL.md`, batch 2P); port only the C++ side. Never translate the scripts. Script functions get `RUN_AS_IS` once its evidence gate passes, never `N_A`. Reference is 40250 `Eternexus/root`, **not** `assets/root` | `extension/src/port/<Lib>/` (bindings), scripts from pack |
 | `platform` | Direct3D/`Grp*`, Granny (`EterGrnLib`), Miles, SpeedTree, `EffectLib`/terrain rendering, Win32 window/input/IME, threads, anti-cheat | Adapter behind the interface the 40250 caller uses; equivalence by observable output | `extension/src/platform/` + existing render code (`metin2_model`, `metin2_anim`, `gr2_bridge`, ...) |
 
 Rules for the `logic` layer:
@@ -48,10 +48,14 @@ Rules for the `logic` layer:
   switch until the new path is wired into the runtime; delete the old logic in the same commit that
   switches its callers to the ported code, leaving only glue (node creation, forwarding Godot input,
   reading ported state to place nodes). A ported function nothing calls at runtime stays `TODO`.
-- Keep 40250 **widths and overflow semantics**, not its C type names: 40250 is Win32, where `long` and
-  `unsigned long` are 32-bit. Use the fixed-width types from `port/common/Win32Types.h`; every
+- Keep 40250 **widths and overflow semantics**, not its C type names: the 40250 executable targets
+  32-bit Win32 (ILP32), where `long`, `unsigned long`, and pointers are 32-bit. `Win32Types.h`
+  supplies fixed-width Win32 scalar aliases, but cannot redefine C++ keywords such as `long`;
+  serialized declarations use explicit fixed-width types. Every
   serialized struct (proto records, packets, EPK index, msa/msm) gets 40250's `#pragma pack` and a
-  `static_assert(sizeof(T) == N)`; pointers stored in `DWORD` become `uintptr_t` with a port-map note.
+  `static_assert(sizeof(T) == N)`. Pointer/handle types stay pointer-sized behind platform adapters;
+  pointers stored in `DWORD` become `uintptr_t` with a port-map note. Arithmetic that relies on
+  32-bit wrap uses unsigned operations or explicit wrapping helpers, never signed-overflow UB.
 - Keep 40250 units (`TPixelPosition` in cm, `DWORD` ms from `ELTimer_GetMSec`, degrees).
   Convert to Godot space only in the adapter.
 - Port in `#include`-dependency order: a shared header belongs to the first unit that needs it, and
@@ -97,6 +101,9 @@ conflicts between parallel rounds). Schema in `references/audit-schema.md`. Func
 
 - `TODO` — not yet compared.
 - `PORTED` — current counterpart is statement-equivalent; `impl` names it.
+- `RUN_AS_IS` — Python source is byte-identical to the reference, packaged and loaded by embedded
+  CPython on a reachable runtime path; `impl` names the packaged script and `evidence` names the
+  target-platform import/runtime proof. It is invalid for C++ units.
 - `ADAPTED` — platform adapter; `note` states both sides and the invariant, with a test.
 - `N_A` — platform plumbing with no gameplay semantics; `note` states why.
 - `DIVERGENT` — known different and not yet fixed; `note` says how.