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/weapons/data/weapon_data.gd

@@ -0,0 +1,51 @@
+## WeaponData — resource containing all stats for a weapon.
+##
+## Used by the weapon system to configure damage, fire rate, recoil,
+## economy pricing, and team restrictions.
+##
+## This is a pure Resource (no Node dependency) so it loads clean
+## in both client and server contexts.
+
+extends Resource
+class_name WeaponData
+
+enum FireMode { SEMI, AUTO, MELEE }
+
+# Identification
+@export var weapon_id: int = 0
+@export var weapon_name: String = ""
+@export var slot: int = 0          # 0=melee, 1=pistol, 2=SMG, 3=rifle, 4=sniper
+
+# Damage
+@export var damage: int = 30
+@export var headshot_multiplier: float = 2.0
+@export var chest_multiplier: float = 1.0
+@export var waist_multiplier: float = 0.75
+@export var leg_multiplier: float = 0.5
+@export var armor_penetration: float = 0.5  # 0.0-1.0, % damage through armor
+
+# Firing
+@export var fire_mode: FireMode = FireMode.SEMI
+@export var fire_rate: float = 10.0          # rounds per second
+@export var reload_time: float = 2.0         # seconds
+@export var max_distance: float = 1000.0
+
+# Magazine
+@export var magazine_size: int = 30
+@export var reserve_size: int = 90
+
+# Recoil & Spread
+@export var recoil_per_shot: float = 0.5     # degrees
+@export var recoil_recovery: float = 8.0     # degrees/sec
+@export var spread_idle: float = 0.0         # degrees while standing still
+@export var spread_walking: float = 2.0      # degrees while moving
+@export var spread_sprinting: float = 6.0    # degrees while sprinting
+
+# Movement
+@export var move_speed_multiplier: float = 1.0  # multiplier on base move speed
+@export var aim_speed_multiplier: float = 0.5   # move speed while aiming
+
+# Economy
+@export var price: int = 0
+@export var kill_reward: int = 300
+@export var team: int = -1   # -1=both, 0=T, 1=CT