fix(physics): P5 commit 3 - retire TS-35, close #167 (ConstraintManager leash)

PhysicsBody.IsFullyConstrained now reflects real ConstraintManager state
(pushed every tick by the same per-tick pumps commit 2 wired), so
jump_is_allowed's already-ported gate (WeenieError 0x47) actually fires
while an object is rubber-banding hard against a server position
correction, closing the last piece of #167.

Housekeeping:
- Delete register row TS-35 (retired: the write side is no longer stubbed).
- Rewrite the stale doc comments on PhysicsBody.IsFullyConstrained,
  ConstraintManager (class + IsFullyConstrained), PositionManager.ConstrainTo,
  EntityPhysicsHost.PositionManager, and PlayerMovementController.PositionManager
  that described the leash as permanently unarmed/stubbed.
- Close #167 in ISSUES.md citing the research doc and commits e0629145 /
  7719d25b.
- Add an "as-ported" addendum to
  docs/research/2026-07-30-constraint-leash-constants.md naming the actual
  current seam owners (the doc's own open question flagged this as
  implementer-verify-required post-J-slices).
- Update docs/plans/2026-07-29-physics-parity-campaign.md's P5 status and
  CLAUDE.md's Campaign P summary to reflect #167's closure (items #153/#72
  remain open in P5).

Verification: complete solution suite green - 9,978 tests, 5 skips, 0
failures across all 9 test projects (Core.Tests, Runtime.Tests, App.Tests,
Headless.Tests, Core.Net.Tests, Content.Tests, UI.Abstractions.Tests,
Bake.Tests, Cli.Tests).

src/AcDream.Core/Physics/Motion/ConstraintManager.cs

@@ -13,16 +13,18 @@ namespace AcDream.Core.Physics.Motion;
 /// <c>CMotionInterp::jump_is_allowed</c> (block jump while
 /// <see cref="IsFullyConstrained"/>).
 ///
-/// <para><b>Arming is UNPORTED in acdream (R5).</b> Retail arms the leash ONLY
-/// from <c>SmartBox::HandleReceivedPosition</c> (on every inbound server
-/// position packet) with two constants from
-/// <c>CPhysicsObj::GetStart/MaxConstraintDistance</c> whose values BN elided
-/// (x87 returns — unknown, need a cdb read). acdream's position reconciliation
-/// is not SmartBox, so nothing calls <see cref="ConstrainTo"/> — the leash
-/// stays disarmed and <see cref="IsFullyConstrained"/> stays false, matching
-/// register TS-35's current stub behavior. The class is ported for structural
-/// completeness of <see cref="PositionManager"/>; the leash-arming port + the
-/// two unknown constants are a deferred issue (port-plan §Constraint scope).</para>
+/// <para><b>Armed as of Campaign P P5 (2026-07-30, #167, closed
+/// register row TS-35).</b> Retail arms the leash ONLY from
+/// <c>SmartBox::HandleReceivedPosition</c> (0x00453fd0, on every inbound
+/// server position packet) with the start/max band from
+/// <c>CPhysicsObj::GetStart/MaxConstraintDistance</c> — byte-decoded (the x87
+/// returns BN elided) in <see cref="ConstraintDistance"/>. acdream's
+/// equivalents call <see cref="ConstrainTo"/> at every accepted-position
+/// seam: <c>LiveEntityNetworkUpdateController</c> for remotes (anchored to
+/// the object's own position, right after the hard-teleport branch returns)
+/// and <c>PlayerMovementController.SetPosition</c>/<c>BlipPosition</c> for
+/// the local player (anchored to the received position). See
+/// <c>docs/research/2026-07-30-constraint-leash-constants.md</c>.</para>
 /// </summary>
 public sealed class ConstraintManager
 {
@@ -77,8 +79,11 @@ public sealed class ConstraintManager
     /// Retail <c>ConstraintManager::IsFullyConstrained</c> (0x005560d0):
     /// <c>constraint_distance_max * 0.9 &lt; constraint_pos_offset</c> — the
     /// object counts as fully constrained once it has strained past 90 % of the
-    /// max leash. Read by <c>jump_is_allowed</c> to block jumps. Always false
-    /// while the leash is disarmed (acdream never arms it — see class note).
+    /// max leash. Read by <c>jump_is_allowed</c> to block jumps. False while
+    /// unconstrained (no prior <see cref="ConstrainTo"/> or after
+    /// <see cref="UnConstrain"/>) since <see cref="ConstraintDistanceMax"/> and
+    /// <see cref="ConstraintPosOffset"/> both default to zero (<c>0*0.9 &lt; 0</c>
+    /// is false).
     /// </summary>
     public bool IsFullyConstrained()
         => ConstraintDistanceMax * 0.9f < ConstraintPosOffset;

src/AcDream.Core/Physics/Motion/PositionManager.cs

@@ -54,8 +54,8 @@ public sealed class PositionManager
 
     /// <summary>Retail <c>PositionManager::ConstrainTo</c> (0x00555280) —
     /// lazily create the <see cref="ConstraintManager"/> and arm the leash.
-    /// (Unused in acdream — no arming call site; see
-    /// <see cref="ConstraintManager"/>.)</summary>
+    /// Armed as of Campaign P P5 (#167) at every accepted-position seam — see
+    /// <see cref="ConstraintManager"/>'s class doc for the call sites.</summary>
     public void ConstrainTo(Position anchor, float startDistance, float maxDistance)
     {
         _constraint ??= new ConstraintManager(_host);

src/AcDream.Core/Physics/PhysicsBody.cs

@@ -408,16 +408,33 @@ public sealed class PhysicsBody
     public double LastUpdateTime { get; set; }
 
     /// <summary>
-    /// R3-W3 stub for retail <c>CPhysicsObj::IsFullyConstrained</c>
-    /// (0x0050f730), read by <c>CMotionInterp::jump_is_allowed</c> (raw
-    /// 305524-305525: <c>if (IsFullyConstrained(physics_obj) != 0) return
-    /// 0x47;</c>). Retail's body walks per-cell contact-plane constraints
-    /// (a mover pinned between opposing walkable surfaces / doorway
-    /// jamming); acdream has no equivalent constraint-tracking yet.
-    /// Register row: stubbed false (never fires) — a real port needs the
-    /// per-cell shadow-list contact accounting the physics digest tracks.
-    /// See docs/architecture/retail-divergence-register.md (added same
-    /// commit as this field).
+    /// Retail <c>CPhysicsObj::IsFullyConstrained</c> (0x0050f730), read by
+    /// <c>CMotionInterp::jump_is_allowed</c> (raw 305524-305525:
+    /// <c>if (IsFullyConstrained(physics_obj) != 0) return 0x47;</c>) to block
+    /// a jump while the object is rubber-banding hard against a server
+    /// position correction.
+    ///
+    /// <para>R3-W3 originally stubbed this as an always-false property under
+    /// a WRONG mechanism guess (per-cell contact-plane / doorway-jamming).
+    /// R5-V1 corrected the mechanism: the real retail source is
+    /// <c>ConstraintManager::IsFullyConstrained</c> (0x005560d0,
+    /// <c>constraint_distance_max * 0.9 &lt; constraint_pos_offset</c>) —
+    /// <see cref="Motion.PositionManager"/>'s constraint sub-manager. R5-V1
+    /// ported <see cref="Motion.ConstraintManager"/> but did not arm it (#167,
+    /// former register row TS-35).</para>
+    ///
+    /// <para>Campaign P P5 (2026-07-30) armed the leash at every current
+    /// inbound-position acceptance seam
+    /// (<c>LiveEntityNetworkUpdateController</c> for remotes,
+    /// <c>PlayerMovementController.SetPosition</c>/<c>BlipPosition</c> for the
+    /// local player — see <c>docs/research/2026-07-30-constraint-leash-constants.md</c>
+    /// §2/§3). <see cref="MotionInterpreter"/> only holds a
+    /// <see cref="PhysicsBody"/> reference (no host), so this property stays a
+    /// plain settable bool; the per-tick pump that already runs
+    /// <c>PositionManager.AdjustOffset</c> (<c>PlayerMovementController.Update</c>,
+    /// <c>RuntimeRemotePhysicsUpdater.Tick</c>/<c>TickHidden</c>) is the single
+    /// owner that pushes <c>PositionManager.IsFullyConstrained()</c> here every
+    /// tick, so this read is now live, not stubbed.</para>
     /// </summary>
     public bool IsFullyConstrained { get; set; }
 

src/AcDream.Runtime/Gameplay/PlayerMovementController.cs

@@ -503,7 +503,11 @@ public sealed class PlayerMovementController
     /// motion) and <c>UseTime</c> after the completed-motions sweep (retail
     /// <c>UpdateObjectInternal</c> tail @0x005159b3 — the sticky 1 s lease
     /// watchdog). <see cref="SetPosition(Vector3, uint, Vector3)"/> tears any
-    /// stick down (retail <c>teleport_hook</c> @0x00514eee).
+    /// stick down (retail <c>teleport_hook</c> @0x00514eee) and, as of
+    /// Campaign P P5 (#167), also tears down and immediately re-arms the
+    /// constraint leash (<c>UnConstrain</c> then <c>ConstrainTo</c>);
+    /// <see cref="BlipPosition"/> arms the leash without tearing it down first
+    /// (retail <c>SmartBox::BlipPlayer</c> survives motion/velocity/stick).
     /// </summary>
     public AcDream.Core.Physics.Motion.PositionManager? PositionManager { get; set; }
 

src/AcDream.Runtime/Physics/EntityPhysicsHost.cs

@@ -170,10 +170,13 @@ public sealed class EntityPhysicsHost : IPhysicsObjHost
     public TargetManager TargetManager => _targetManager;
 
     /// <summary>R5-V3 — the owned <see cref="PositionManager"/> facade (retail
-    /// <c>CPhysicsObj::position_manager</c>): sticky follow + (unarmed)
-    /// constraint leash. Seam targets: <c>MoveToManager.StickTo/Unstick</c>,
+    /// <c>CPhysicsObj::position_manager</c>): sticky follow + the
+    /// server-position constraint leash (armed as of Campaign P P5, #167).
+    /// Seam targets: <c>MoveToManager.StickTo/Unstick</c>,
     /// <c>MotionInterpreter.UnstickFromObject</c>, the per-tick
-    /// <c>AdjustOffset</c>/<c>UseTime</c> drivers.</summary>
+    /// <c>AdjustOffset</c>/<c>UseTime</c> drivers, and
+    /// <c>LiveEntityNetworkUpdateController</c>'s remote-position
+    /// <c>ConstrainTo</c> arm.</summary>
     public PositionManager PositionManager { get; }
 
     // ── IPhysicsObjHost fan-out / target-tracking seams ────────────────────