port 2V2-d.1: ActorInstance/InstanceBase closure creates the main character

Port the ActorInstance*/InstanceBase* siblings plus GameUtil, FlyTarget,
PhysicsObject, GameEventManager, WeaponTrace, MapUtil and lineintersect_utils
verbatim and drop their pending stand-ins; CGameEventManager and CPythonSystem
join PythonBoot in CPythonApplication member order.

Root cause of the intermittent Loading-phase header 7: TPlayerSkill::tNextRead
is time_t, 32-bit in 40250 (_USE_32BIT_TIME_T) but 64-bit on LP64, so
SKILL_LEVEL (76) was read as 2551 bytes instead of 1531. Packet.h now uses
LONG with a static_assert, and the fake server sends SKILL_LEVEL in Loading.

The fake server's CHARACTER_ADD now uses CHAR_TYPE_PC; port.login_flow
asserts the main instance exists with race 0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

audit/port-map/EterLib/lineintersect_utils.cpp.json

@@ -0,0 +1,32 @@
+{
+  "reference": "EterLib/lineintersect_utils.cpp",
+  "reference_sha256": "4636f73c1ac19ad36b9a487827debb9684679fb9d0c912f7308f04dd649cdac2",
+  "priority": "P4",
+  "contracts": [],
+  "functions": {
+    "FindNearestPointOnLineSegment": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/lineintersect_utils.cpp:FindNearestPointOnLineSegment"
+      ]
+    },
+    "FindNearestPointOfParallelLineSegments": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/lineintersect_utils.cpp:FindNearestPointOfParallelLineSegments"
+      ]
+    },
+    "AdjustNearestPoints": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/lineintersect_utils.cpp:AdjustNearestPoints"
+      ]
+    },
+    "IntersectLineSegments": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/lineintersect_utils.cpp:IntersectLineSegments"
+      ]
+    }
+  }
+}