feat(physics): port retail projectile integration

Add a pure Core projectile driver for retail clock quanta, final-state acceleration, 50-unit velocity clamping, world-space angular integration, full-3D AlignPath, and oriented Setup-local sphere sweeps. Preserve exact success versus set_frame-only failure semantics, independent Contact/OnWalkable state, and full-cell identity across all landblock directions.

Port OBJECTINFO::missile_ignore with explicit weenie/creature metadata, remove the invented transition-step cap, retain PathClipped without arming PerfectClip, and keep authoritative target identity optional. Add malformed-shape/clock, thin-wall, terrain, target-exclusion, frame-spike, failure-state, and boundary conformance coverage.

Retire TS-2 and synchronize the architecture, milestones, roadmap, research oracle, and durable physics memory.

Co-Authored-By: Codex <noreply@openai.com>

src/AcDream.Core/Physics/EntityCollisionFlags.cs

@@ -39,6 +39,14 @@ public enum EntityCollisionFlags : byte
     IsPKLite       = 0x08,
     /// <summary>Set when <c>BF_FREE_PKSTATUS (0x200000)</c> is set (a.k.a. "Free" PK status — cannot be PKed).</summary>
     IsImpenetrable = 0x10,
+    /// <summary>
+    /// Runtime collision metadata: the target has a retail
+    /// <c>CWeenieObject</c>. This is deliberately distinct from
+    /// <see cref="IsCreature"/> because doors, portals, and items also have a
+    /// weenie. <c>OBJECTINFO::missile_ignore</c> at <c>0x0050CEB0</c>
+    /// requires this distinction for ethereal targets.
+    /// </summary>
+    HasWeenie      = 0x20,
 }
 
 /// <summary>Helpers to convert raw retail bitfields into <see cref="EntityCollisionFlags"/>.</summary>