Stage 1: walk while healing legs, for SPT 4.0.13

Ground-up reimplementation of yox92/SmartAction targeting SPT 4.0.13 /
EFT 0.16.9.0.40087. Only the walk-while-healing feature is implemented;
see NOTES.md for status and the deferred sprint work.

Design departures from upstream:

- CanWalk is a guarded postfix, not a transpiler. Upstream rewrote the
  method body, which affects every MovementContext in the raid including
  bots, and is hard-incompatible with the three other mods already
  patching MovementContext in a typical load order (SAIN, ORBIT,
  maschine-DualSideDoorBreach). A postfix that only flips false -> true
  for IsYourPlayer is inert for other entities by construction.

- The postfix re-tests ObstacleCollisionFacade_1.CanMove() before
  lifting. Upstream's transpiler dropped that check along with the
  HealingLegs check, silently disabling obstacle blocking.

- Targets resolve by name via AccessTools.PropertyGetter + nameof rather
  than by GClass number, so they survive EFT version bumps.

Verified in-game against 78 loaded plugins: both patches attach, the
guard rejected 985 non-local MovementContext calls with zero leaks, and
_player was never null across ~4000 guard calls.

CanSprintPatch is parked in deferred/ rather than deleted:
MovementContext.CanSprint does not gate sprinting (EnableSprint calls
Physical.Sprint unconditionally), and forcing it true makes EnableSprint
run ForceStopInteractions()/RemoveLeftHandItem() mid-heal. Details and
the 3.11 -> 4.0.13 rename table are in NOTES.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

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+# SmartAction — SPT 4.0.x
+
+Lets you **walk while healing a leg** in SPT.
+
+Targets **SPT 4.0.13 / EFT 0.16.9.0.40087**, BepInEx 5, `netstandard2.1`.
+
+---
+
+## Attribution
+
+This is a reimplementation of **[yox92/SmartAction](https://github.com/yox92/SmartAction)**,
+which targets an earlier SPT version. The feature idea, the original research into which
+EFT internals to touch, and the name are yox92's work.
+
+**Upstream ships no LICENSE file.** If you intend to redistribute this or build on it,
+ask yox92 for an explicit license first — absence of a license means all rights reserved,
+and that applies to derivatives too.
+
+This is not a drop-in port. The patches were rewritten rather than translated; see
+[NOTES.md](NOTES.md) for what changed and why.
+
+---
+
+## Status
+
+| Feature | Status |
+|---|---|
+| Walk while healing legs | Working |
+| Sprint while using meds | **Not implemented** — see NOTES.md |
+| Adaptive heal speed | Not implemented |
+| Quick-cancel surgery | Not implemented |
+
+Only the first feature exists today. The rest of upstream's feature set is unported.
+
+## Install
+
+Drop `SmartAction.dll` into `BepInEx/plugins/SmartAction/`.
+
+## Build
+
+Requires the .NET SDK. Reference assemblies are read from a local SPT install:
+
+```bash
+dotnet build -c Release -p:SptDir=/path/to/SPT
+```
+
+Add `-p:DeployToGame=true` to copy the result straight into `BepInEx/plugins/SmartAction/`.
+
+No BSG or SPT assemblies are redistributed here — the build reads them from your own install.
+
+## Multiplayer / Fika
+
+The patch is guarded on `IsYourPlayer` and only ever grants movement, never removes it, so
+it is inert for bots and remote players by construction. Verified in a live raid: 985 guard
+rejections of non-local `MovementContext` instances with zero leaks, alongside SAIN, ORBIT
+and maschine-DualSideDoorBreach, all of which also patch `MovementContext`.
+
+No Fika dependency, no custom packets. It does not touch authoritative health state.
+
+## Config
+
+`BepInEx/config/com.yox92.smartaction.cfg`
+
+| Setting | Default | Purpose |
+|---|---|---|
+| `Diagnostics` | `true` | Logs patch/guard activity and a counter summary every 30s. Turn off once you trust it. |