Add body-camera timeline to the shift review

- New src/game/ui/event_timeline.gd flattens every recorded incident event
  (ADR-0005) into one time-ordered list and shows time, person, and a one-line
  summary. Step with Left/Right or the buttons; Esc returns to the review. No live
  3D replay in this first version.
- Shift review gains a "Body camera timeline" button that hands the review to the
  timeline; the review dim is hidden while it is open (stacked overlays made the
  screen nearly black) and restored on close.
- ShiftCoordinator records started_at_ms so the review can stamp events as mm:ss.
- 8 new string keys for the timeline UI and the review button.

Tests/docs
- Headless suite 113 -> 120 (test_event_timeline.gd), new smoke_timeline.gd that
  opens the timeline from the review, steps through every event, and closes back.
- README, TODO section moved to DONE, MEMORY notes. Version 0.2.6.

src/test/smoke_timeline.gd

@@ -0,0 +1,83 @@
+extends SceneTree
+## Body-camera timeline smoke: records a few real interactions, opens the review's
+## timeline, steps through every event, and closes back to the review.
+##
+## Usage:
+##   godot --headless --path . --script res://src/test/smoke_timeline.gd
+
+const MAX_FRAMES := 900
+
+var frame := 0
+var gm: Node = null
+var started := false
+var step := 0
+var failures: Array[String] = []
+
+func _initialize() -> void:
+	root.size = Vector2i(1280, 720)
+	root.add_child(load("res://scenes/main.tscn").instantiate())
+
+func _process(_delta: float) -> bool:
+	frame += 1
+	if gm == null:
+		gm = root.find_child("GameManager", true, false)
+		return false
+	if not started:
+		gm.call("_on_venue_selected", "hollywood_building")
+		started = true
+		return false
+	if frame > MAX_FRAMES:
+		_fail("timeout")
+		return true
+	if frame < 200:
+		return false
+	match step:
+		0:
+			if gm.npcs.is_empty():
+				return false
+			gm.call("_on_guard_target", gm.npcs[0])
+			gm.call("_apply_interaction", 1, "eye contact")
+			gm.call("_request_reason")
+			gm.call("_apply_interaction", 2, "formal warning")
+			var review: Dictionary = gm.coordinator.build_review()
+			# Real flow: the review screen shows first, then its timeline button.
+			gm.shift_review_panel.show_review(review, gm.selected_scenario, [])
+			var button: Button = gm.shift_review_panel.find_child("TimelineButton", true, false) as Button
+			_check(button != null, "review offers a body-camera timeline button")
+			if button:
+				button.pressed.emit()
+			var count: int = gm.event_timeline.events.size()
+			_check(count >= 3, "timeline collected the interaction events (%d)" % count)
+			_check(gm.event_timeline.visible, "timeline is showing")
+			_check(not gm.shift_review_panel.visible, "review is hidden behind the timeline")
+			_check(gm.guard.input_locked, "the guard is frozen while the timeline is open")
+			for i in count + 2:
+				gm.event_timeline.step(1)
+			_check(gm.event_timeline.index == count - 1, "stepping clamps at the last event")
+			gm.event_timeline.close()
+			step = 1
+		1:
+			_check(not gm.event_timeline.visible, "timeline closes")
+			_check(gm.shift_review_panel.visible, "closing returns to the review")
+			_finish()
+			return true
+	return false
+
+func _check(condition: bool, message: String) -> void:
+	if condition:
+		print("ok: " + message)
+	else:
+		_fail(message)
+
+func _fail(message: String) -> void:
+	failures.append(message)
+	_finish()
+
+func _finish() -> void:
+	if failures.is_empty():
+		print("SMOKE OK: body-camera timeline")
+		quit(0)
+	else:
+		for message in failures:
+			printerr("SMOKE FAIL: " + message)
+		quit(1)