Save workspace artifacts: character-controller, gdextension scaffold, network scripts, map-pipeline, server config

Includes code from task workspaces that was never pushed:
- client/characters/ — fps_character_controller.gd (400 lines), fps_camera.gd, input_handler.gd
- gdextension/simulation/ — C++ GDExtension scaffold: entity, movement, hit detection, simulation server, state serializer, bitstream (14 files)
- scripts/network/ — ENet-based network_manager.gd, server/client_main.gd, player.gd
- scripts/map_packaging/ — PCK pipeline: pack_map.gd, map_downloader.gd, map_registry_server.py, README
- scripts/config/ — server_config.gd (480 lines)
- scenes/ — client_main, server_main, player, test_range
- project.godot, export_presets.cfg

export_presets.cfg

@@ -0,0 +1,47 @@
+[preset.0]
+name="Linux Server"
+platform="Linux/X11"
+runnable=true
+dedicated_server=true
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="build/tactical-shooter-server.x86_64"
+patches=PackedStringArray()
+encryption_include_filters=""
+encryption_exclude_filters=""
+encrypt_pck=false
+encrypt_directory=false
+script_encryption_key=""
+
+[preset.0.options]
+custom_template/debug=""
+custom_template/release=""
+binary_format/embed_pck=true
+binary_format/architecture="x86_64"
+texture_format/s3tc_bptc=true
+texture_format/etc2_astc=false
+texture_format/no_bptc_fallbacks=true
+dotnet/include_scripts_content=false
+dotnet/rollforward_to_latest_prerelease=true
+codesign/identity=""
+codesign/timestamp=true
+codesign/timestamp_server_url=""
+application/icon=""
+application/identifier="tactical-shooter-server"
+application/name="Tactical Shooter Server"
+application/app_category="game"
+application/file_version="0.1.0"
+application/product_version="0.1.0"
+application/company_name=""
+application/copyright=""
+application/trademarks=""
+display/width=1
+display/height=1
+display/handheld/dpi=72
+display/handheld/dpi_mode="disabled"
+display/scale_mode="disabled"
+xr_features/enabled=false
+xr_features/hand_tracking=false
+xr_features/passthrough=false