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
