feat(R3-W2): pending_motions lifecycle + the MotionDone consumer — the R2 seam lands (closes J1, J17)

MotionInterpreter implements IMotionDoneSink: pending_motions
(LinkedList<MotionNode>, AD-34 wording) + add_to_queue 0x00527b80 +
motions_pending 0x00527fe0 + MotionDone 0x00527ec0 verbatim (action-class
head → UnstickFromObject no-op seam (→R5 StickyManager) + BOTH states'
action-FIFO pops; head popped UNCONDITIONALLY — A7: never match-by-id,
params unread in this build) + HandleExitWorld 0x00527f30 (the raw
decompile's null-physics-obj branch would infinite-loop if translated
literally — adjudicated as retail dead code, documented on the method) +
is_standing_still 0x00527fa0 + MotionAllowsJump 0x005279e0 with the
A1-pinned literal blocklist (28-case boundary table test: Fallen blocks,
Falling passes — ACE's transposition NOT copied).

Queue producers wired into the funnel per the decomp anchors
(re-verified from the raw text): DispatchInterpretedMotion's success
path computes jump_error_code via retail's double-check shape
(motion_allows_jump(motion), then forward_command when non-action;
the DisableJumpDuringLink params leg is TODO(W5) — no MovementParameters
threaded yet) + add_to_queue; apply_interpreted_movement's turn-stop
re-queues the Ready node (@305766-305785 — the plan's producer #2 and #3
are the SAME site; StopInterpretedMotion's internal add_to_queue @305657
is W5 scope). ContextId=0 with TODO(W5): retail's own compiled code
reads an UNINITIALIZED local for it at this call site.

GameWindow: MotionDoneTarget now binds the entity's REAL consumer —
player via PlayerMovementController.Motion (new internal property),
remotes via RemoteMotion.Motion — resolved AT FIRE TIME (a remote's
RemoteMotion can be created after its first anim tick; an eager capture
would drop completions forever). Despawn runs BOTH layers' exit-world
drains (manager then interp) per §4. AD-36 narrowed (consumed for
creature-class; doors/statics recorder-only until R5).

51 new conformance cases incl. the end-to-end chain test:
MotionTableManager.AnimationDone → sink → interp pending head pops in
step. 183-case observer-trace + funnel suites green unchanged (queue
side effects additive). Full suite: 3,582 passed.

Implemented by a dedicated agent (MotionInterpreter side) against the
W0-pinned spec; producer placements + MotionAllowsJump branch algebra
independently reviewed against the raw decomp; GameWindow wiring by the
orchestrator.

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

src/AcDream.App/Input/PlayerMovementController.cs

@@ -360,6 +360,15 @@ public sealed class PlayerMovementController
         _weenie.SetSkills(runSkill, jumpSkill);
     }
 
+    /// <summary>
+    /// R3-W2 (r3-port-plan.md §4): the player's <see cref="MotionInterpreter"/>
+    /// — GameWindow binds the player sequencer's MotionDone seam to it so the
+    /// pending_motions queue pops in step with animation completion, same
+    /// path remotes use. R3-W6 widens this into the full local-player
+    /// unification.
+    /// </summary>
+    internal MotionInterpreter Motion => _motion;
+
     /// <summary>
     /// Wire the player's AnimationSequencer current cycle velocity into
     /// <see cref="MotionInterpreter.GetCycleVelocity"/>.  When attached,