Phase 7: netfox + godot-jolt stack upgrade

Stack installed:
- netfox v1.35.3 (core + extras + noray + internals)
- godot-jolt v0.16.0-stable

Architecture:
- Server: ENet transport (works headless, no netfox deps)
- Client/Editor: netfox rollback (RollbackSynchronizer, TickInterpolator)

New/modified:
- docs/migration-netfox-plan.md — migration architecture
- scripts/network/network_manager.gd — netfox-aware ENet fallback
- scripts/network/player.gd — clean base player
- client/characters/player_netfox.gd — rollback player w/ WeaponManager
- client/characters/input/player_net_input.gd — BaseNetInput subclass
- client/characters/character/fps_character_controller.gd — netfox input feed
- client/weapons/ — weapon data, registry, TacticalWeaponHitscan, WeaponManager
- client/scripts/round_replicator.gd — client-side round state bridge
- server/scripts/round_manager.gd — improved state machine
- server/scripts/plugin_api/plugin_manager.gd — refined plugin system
- config: enemy_tag, ally_tag for meatball targeting

Removed: old C++ SimulationServer GDExtension (replaced by netfox rollback)

client/project.godot.orig

@@ -0,0 +1,49 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=5
+
+[animation]
+
+compatibility/default_parent_skeleton_in_mesh_instance_3d=true
+
+[application]
+
+config/name="Tactical Shooter"
+config/description="A competitive round-based tactical FPS"
+run/main_scene="res://bake_lightmaps.tscn"
+config/features=PackedStringArray("4.3")
+
+[autoload]
+
+MapDownloader="*res://scripts/map_downloader.gd"
+
+[input]
+
+use_accumulated_input=false
+
+[memory]
+
+limits/message_queue_max_size_kb=2048
+
+[physics]
+
+common/physics_ticks_per_second=128
+
+[rendering]
+
+renderer/rendering_method.mobile="glcompatibility_4"
+rendering/lightmapping/texel_scale=1.0
+rendering/reflections/reflection_atlas/reflection_size=512
+rendering/reflections/reflection_atlas/reflection_count=8
+rendering/lights_and_shadows/positional_shadow/atlas_size=2048
+rendering/lights_and_shadows/positional_shadow/atlas_quadrant_0_subdiv=1
+rendering/lights_and_shadows/positional_shadow/atlas_quadrant_1_subdiv=2
+rendering/lights_and_shadows/positional_shadow/atlas_quadrant_2_subdiv=3
+rendering/limits/buffers/vertex_buffer_max_size=256
+rendering/limits/buffers/index_buffer_max_size=128