port: complete 100% logic layer, eliminate pending dir, and unify client_main on port route

- Completed batch 4-f (Messenger, Guild, GuildMark), 4-g (PythonSystem, systemSetting), 4-h (PythonSoundManagerModule, MilesLib CSoundManager)
- Ported UserInterface/Locale.cpp, EterLocale/Japanese.cpp, EterLib/PathStack, EterLib/NetDatagram* UDP suite
- Modularized PythonApplication into Camera and Event handlers aligning with 40250 signatures
- Completely removed extension/src/platform/pending/ directory
- Logic layer reached 100.0% completion (3338/3338 functions, 0 TODO, 0 DIVERGENT) with empty port-map queue
- Removed legacy AppFlow route and fallback from project/client_main.gd, switching main loop unconditionally to native port route
- Verified 15/15 port.login_flow integration steps and 19/19 port_gate suites passing

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

@@ -0,0 +1,56 @@
+{
+  "reference": "EterLib/PathStack.cpp",
+  "reference_sha256": "ad341731d521be4c11930a16d2d7257d9b93b19e2e27c3b122079699fa067f5e",
+  "priority": "P4",
+  "contracts": [],
+  "functions": {
+    "CPathStack::CPathStack": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::CPathStack"
+      ]
+    },
+    "CPathStack::~CPathStack": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::~CPathStack"
+      ]
+    },
+    "CPathStack::GetCurrentPathName": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::GetCurrentPathName"
+      ]
+    },
+    "CPathStack::Push": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::Push"
+      ]
+    },
+    "CPathStack::Pop": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::Pop"
+      ]
+    },
+    "CPathStack::MoveBase": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::MoveBase"
+      ]
+    },
+    "CPathStack::SetBase": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::SetBase"
+      ]
+    },
+    "CPathStack::Move": {
+      "status": "PORTED",
+      "impl": [
+        "extension/src/port/EterLib/PathStack.cpp:CPathStack::Move"
+      ]
+    }
+  }
+}