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>

Patch/CanWalkPatch.cs

@@ -0,0 +1,59 @@
+using System.Reflection;
+using EFT;
+using HarmonyLib;
+using SPT.Reflection.Patching;
+
+namespace SmartAction.Patch;
+
+/// <summary>
+/// Lets you walk while healing a leg.
+///
+/// Vanilla MovementContext.CanWalk (EFT 0.16.9.0.40087):
+///     if (PhysicalConditionIs(HealingLegs))      return false;
+///     if (!ObstacleCollisionFacade_1.CanMove())  return false;
+///     return true;
+///
+/// Upstream SmartAction replaced this body with a transpiler, which rewrote the method for
+/// every MovementContext in the raid — bots included — and dropped the obstacle check along
+/// with the HealingLegs check. A postfix that only ever flips false -> true is per-instance,
+/// composes with other movement mods, needs no IL matching, and keeps CanMove() intact.
+/// </summary>
+public class CanWalkPatch : ModulePatch
+{
+    protected override MethodBase GetTargetMethod()
+    {
+        return AccessTools.PropertyGetter(typeof(MovementContext), nameof(MovementContext.CanWalk));
+    }
+
+    [PatchPostfix]
+    private static void Postfix(MovementContext __instance, ref bool __result)
+    {
+        // Never grant movement vanilla already allows, and never take it away.
+        if (__result) return;
+
+        if (!MovementPatchUtil.IsLocalPlayer(__instance)) return;
+
+        // Only intervene when healing is the reason we were blocked.
+        if (!__instance.PhysicalConditionIs(EPhysicalCondition.HealingLegs)) return;
+
+        // The other vanilla blocker still applies: if something is physically in the way,
+        // leave the false alone. (Null facade -> treat as blocked.)
+        if (__instance.ObstacleCollisionFacade_1?.CanMove() != true)
+        {
+            if (Diagnostics.Enabled)
+            {
+                Diagnostics.WalkHeldByObstacle++;
+                Diagnostics.OnceWalkHeldByObstacle();
+            }
+            return;
+        }
+
+        __result = true;
+
+        if (Diagnostics.Enabled)
+        {
+            Diagnostics.WalkLifted++;
+            Diagnostics.OnceWalkLifted();
+        }
+    }
+}