Ship the 0.8.0 first-hour and campaign milestone

Add the campaign shell, pause-safe checkpoint resume, post-shift campaign
continue, confirmed campaign reset, difficulty presets, searchable Help,
content-matrix validation, recovery events, contextual dialogue, policy/debrief
context and eligible-event previews. Extend persistence with atomic separate
files and add campaign/checkpoint/tutorial smokes. Headless 247/247, Python
94/94, tutorial/campaign/session/scenario smokes green.

src/test/smoke_campaign.gd

@@ -0,0 +1,70 @@
+extends SceneTree
+## Campaign shell + checkpoint smoke. Use an isolated user-data dir:
+##   XDG_DATA_HOME=/tmp/gigline-campaign godot --path . --fixed-fps 60 \
+##     --script res://src/test/smoke_campaign.gd
+
+var gm: Node = null
+var frames := 0
+var step := 0
+var failures: Array[String] = []
+
+func _initialize() -> void:
+	root.size = Vector2i(960, 540)
+	root.add_child(load("res://scenes/main.tscn").instantiate())
+
+func _process(_delta: float) -> bool:
+	frames += 1
+	if gm == null:
+		gm = root.find_child("GameManager", true, false)
+		return false
+	match step:
+		0:
+			if frames < 5: return false
+			gm.call("_on_venue_selected", "hollywood_building")
+			gm.coordinator.elapsed_s = 123.0
+			gm.call("_save_shift_checkpoint")
+			gm.call("_show_start_menu")
+			_check(gm.start_menu.visible, "campaign menu opens")
+			_check(gm.start_menu.find_child("ContinueButton", true, false) != null,
+				"continue button exists")
+			step = 1
+			frames = 0
+		1:
+			if frames < 4: return false
+			gm.call("_on_campaign_continue")
+			step = 2
+			frames = 0
+		2:
+			if frames < 20: return false
+			_check(gm.active_scenario_id == "hollywood_building", "resume keeps the venue")
+			_check(gm.coordinator.elapsed_s >= 123.0, "resume keeps elapsed time")
+			gm.call("_on_shift_ended", gm.coordinator.build_review())
+			_check(gm.campaign.shift_number == 2, "campaign advances after a shift")
+			_check(gm.campaign.next_venue() == "joke_shop", "next venue is the Joke Shop")
+			gm.call("_on_review_continue")
+			step = 3
+			frames = 0
+		3:
+			if frames < 20: return false
+			_check(gm.active_scenario_id == "joke_shop", "review continue starts the next venue")
+			gm.call("_open_help")
+			_check(gm.help_overlay.visible, "help overlay opens")
+			gm.help_overlay.close_panel()
+			_finish()
+	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: campaign, checkpoint resume, review continue, help")
+		quit(0)
+	else:
+		for message in failures: printerr("SMOKE FAIL: " + message)
+		quit(1)