Implement TODO backlog: LATE phase fix, protester, CALL_SOMEONE, door lock, flashlight, persistence, navmesh, JSON localization, and release tooling

- Fix LATE shift phase (start 700s) so the violent-threat event is reachable
- Add PROTESTER archetype (rules, profile, colors, events in public venues)
- Add CALL_SOMEONE reaction (FSM -> ARGUING, influencer/trespasser/protester weights)
- Door lock: DoorState core class, L binding, red/green visual indicator,
  locked doors thwart FORCE_ENTRY
- Flashlight: G binding, SpotLight3D, perception radius bonus at evening/late
- Persistence: save shift results via Save autoload, history + best score on
  review screen, round-trip test
- Navigation: flat NavigationRegion3D navmesh, NavigationAgent3D path following
  with direct-movement fallback; steps made visual-only so NPCs reach entrance
- Localization: strings moved to content/strings.en.json (loader keeps
  lookup/fmt signatures; coverage test over all keys)
- Distribution: export_presets.cfg (Linux/Windows/macOS), tools/build_releases.sh,
  docs/RELEASING.md, prominent README Downloads section
- Remove stale signal_bus.gd (invalid static-signal experiment)
- Tests: 53 passing across 9 suites

export_presets.cfg

@@ -0,0 +1,105 @@
+[preset.0]
+
+name="Linux"
+platform="Linux/X11"
+runnable=true
+advanced_options=false
+dedicated_server=false
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="build/step-line-linux.x86_64"
+patches=PackedStringArray()
+encryption_include_filters=""
+encryption_exclude_filters=""
+seed=0
+encrypt_pck=false
+encrypt_directory=false
+script_export_mode=2
+
+[preset.0.options]
+
+custom_template/debug=""
+custom_template/release=""
+debug/export_console_wrapper=1
+binary_format/embed_pck=false
+texture_format/s3tc_bptc=true
+texture_format/etc2_astc=false
+binary_format/architecture="x86_64"
+ssh_remote_deploy/enabled=false
+
+[preset.1]
+
+name="Windows Desktop"
+platform="Windows Desktop"
+runnable=true
+advanced_options=false
+dedicated_server=false
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="build/step-line-windows.exe"
+patches=PackedStringArray()
+encryption_include_filters=""
+encryption_exclude_filters=""
+seed=0
+encrypt_pck=false
+encrypt_directory=false
+script_export_mode=2
+
+[preset.1.options]
+
+custom_template/debug=""
+custom_template/release=""
+debug/export_console_wrapper=0
+binary_format/embed_pck=false
+texture_format/s3tc_bptc=true
+texture_format/etc2_astc=false
+codesign/enable=false
+codesign/timestamp=true
+codesign/identity_type=0
+application/modify_resources=true
+application/icon=""
+application/console_wrapper_icon=""
+application/icon_interpolation=4
+
+[preset.2]
+
+name="macOS"
+platform="macOS"
+runnable=true
+advanced_options=false
+dedicated_server=false
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="build/step-line-macos.zip"
+patches=PackedStringArray()
+encryption_include_filters=""
+encryption_exclude_filters=""
+seed=0
+encrypt_pck=false
+encrypt_directory=false
+script_export_mode=2
+
+[preset.2.options]
+
+custom_template/debug=""
+custom_template/release=""
+debug/export_console_wrapper=0
+binary_format/embed_pck=false
+texture_format/s3tc_bptc=true
+texture_format/etc2_astc=false
+codesign/enable=false
+codesign/timestamp=true
+codesign/identity_type=0
+application/bundle_identifier="biz.allucanget.step-line"
+application/icon=""
+application/icon_interpolation=4
+application/export_angle=0
+application/target_os_version=""
+application/signature_flags=0
+application/show_bundle_name=1