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

src/test/tests/test_door_and_flashlight.gd

@@ -0,0 +1,46 @@
+extends RefCounted
+## Headless tests for the door lock mechanic and flashlight perception bonus.
+
+const Rules := preload("res://src/core/rules.gd")
+const DoorState := preload("res://src/core/door_state.gd")
+const NpcProfile := preload("res://src/core/npc_profile.gd")
+const NPCController := preload("res://src/core/npc_controller.gd")
+
+func test_door_toggle_transitions() -> bool:
+	var door := DoorState.new()
+	var a := TestUtils.check_eq(door.locked, false, "starts unlocked")
+	var b := TestUtils.check_eq(door.toggle(), true, "toggle locks")
+	var c := TestUtils.check_eq(door.toggle(), false, "toggle unlocks")
+	return a and b and c
+
+func test_locked_door_thwarts_force() -> bool:
+	var door := DoorState.new()
+	door.set_locked(true)
+	var result := door.attempt_force()
+	var a := TestUtils.check_eq(result["succeeded"], false, "locked door blocks forced entry")
+	var b := TestUtils.check_eq(result["outcome"], "thwarted", "thwarted outcome")
+	return a and b
+
+func test_unlocked_door_admits_force() -> bool:
+	var door := DoorState.new()
+	var result := door.attempt_force()
+	var a := TestUtils.check_eq(result["succeeded"], true, "open door lets forced entry through")
+	var b := TestUtils.check_eq(result["outcome"], "entered", "entered outcome")
+	return a and b
+
+func test_flashlight_widens_perception() -> bool:
+	## Without the flashlight, an NPC at AWARE_RADIUS + 3 m is unaware.
+	## With the flashlight bonus (4 m), the same distance registers as aware.
+	var p := NpcProfile.new()
+	p.id = "nightwalker"
+	p.npc_type = Rules.NpcType.TOURIST
+	var dim := NPCController.new()
+	dim.setup("d1", p, "wander", 1)
+	var unlit: Dictionary = dim.perceive_guard(NPCController.AWARE_RADIUS + 3.0, 0.0)
+	var a := TestUtils.check_eq(unlit["band"], "unaware", "unlit: too far to notice")
+
+	var lit := NPCController.new()
+	lit.setup("l1", p, "wander", 2)
+	var lit_result: Dictionary = lit.perceive_guard(NPCController.AWARE_RADIUS + 3.0, 4.0)
+	var b := TestUtils.check_eq(lit_result["band"], "aware", "flashlight bonus makes NPC aware")
+	return a and b