fix(save): back-fill state.resources and state.harvested on load

scripts/colony_sim.gd

@@ -46,6 +46,14 @@ func colony_stance() -> String:
 ## Fill in any state keys missing from older saves or fresh bootstraps so the
 ## rest of the sim can mutate them without existence checks.
 func ensure_defaults() -> void:
+	# The economy dictionaries are read unconditionally on the first tick
+	# (apply_food_upkeep, gather_haul_tasks, do_gather); a save that omits
+	# either would crash the sim (issue #378). migrate_save back-fills them on
+	# load, but bootstrap and any direct state assignment go through here too.
+	if not state.has("resources") or not state["resources"] is Dictionary:
+		state["resources"] = {"wood": 0, "stone": 0, "food": 0}
+	if not state.has("harvested") or not state["harvested"] is Dictionary:
+		state["harvested"] = {"wood": 0, "stone": 0, "food": 0}
 	if not state.has("reserved_resources"):
 		state["reserved_resources"] = {}
 	if not state.has("events"):

scripts/game_state.gd

@@ -404,6 +404,17 @@ func validate_save_schema(data: Dictionary) -> Dictionary:
 
 # ── Schema helpers ──────────────────────────────────────────────────────────
 
+# Back-fills the economy dictionaries the sim reads unconditionally on the
+# first tick after load (issue #378): state.resources and state.harvested.
+# bootstrap_state always sets both, but the load path historically did not,
+# so a save omitting either crashed ColonySim on the first process_tick.
+# Existing values are preserved; only missing keys are filled.
+func _backfill_required_state(data: Dictionary) -> void:
+	if not data.has("resources") or not data["resources"] is Dictionary:
+		data["resources"] = {"wood": 0, "stone": 0, "food": 0}
+	if not data.has("harvested") or not data["harvested"] is Dictionary:
+		data["harvested"] = {"wood": 0, "stone": 0, "food": 0}
+
 # Compute valid tile counts from the LayoutMath anchor family configuration.
 # Legacy grid sizes (25/36/64/100/150) are still accepted so historical saves
 # remain loadable until they are migrated.
@@ -501,6 +512,15 @@ func _validate_active_rewards(rewards: Array) -> String:
 	return ""
 
 func migrate_save(data: Dictionary) -> Dictionary:
+	# Back-fill the two economy dictionaries the sim reads unconditionally on
+	# the first tick after load (issue #378). bootstrap_state always sets both,
+	# but a hand-edited, corrupted, or future-migrated save can omit either;
+	# without this, ColonySim.apply_food_upkeep / gather_haul_tasks / do_gather
+	# raise on state.resources.get(...) / state.harvested[...] against a
+	# missing key. Applied before the version branching so every valid return
+	# path carries both fields; the invalid paths return a fresh {} and the
+	# mutation is discarded.
+	_backfill_required_state(data)
 	# Missing version key means "current" — backward compatible
 	if not data.has("save_version"):
 		data["save_version"] = SAVE_VERSION

scripts/main.gd

@@ -1700,6 +1700,11 @@ func next_unlock_text() -> String:
 	return "%s tier unlocked. Keep the tiny settlement fed" % cap(last_kind)
 
 func is_save_compatible(loaded: Dictionary) -> bool:
+	# The sim reads state.resources unconditionally on the first tick after
+	# load (issue #378); a save without a well-typed resources dictionary is
+	# incompatible even if its geometry checks out.
+	if not loaded.has("resources") or not loaded["resources"] is Dictionary:
+		return false
 	var tiles: Array = loaded.get("tiles", [])
 	if tiles.size() != grid_w * grid_h:
 		return false

tests/test_local_storage_load_validation.gd

@@ -28,6 +28,10 @@ func run_tests() -> void:
 	flow_v1_is_migrated_to_v2_with_spawn_tick()
 	flow_valid_v2_is_returned_as_is()
 	flow_empty_local_storage_falls_back_to_fresh_start()
+	flow_missing_resources_backfilled_web()
+	flow_missing_harvested_backfilled_web()
+	flow_missing_resources_backfilled_desktop()
+	flow_missing_harvested_backfilled_desktop()
 	teardown()
 
 func setup() -> void:
@@ -135,3 +139,83 @@ func flow_empty_local_storage_falls_back_to_fresh_start() -> void:
 		empty.is_empty() or (empty.has("save_version") and empty.get("save_version") is int),
 		"empty localStorage yields a fresh-start save shape"
 	)
+
+# 5) A web save missing state.resources is back-filled by migrate_save
+#    (issue #378) so the sim doesn't crash on the first tick after load.
+#    Previously validate_save_schema only checked resources "if present", so
+#    this fixture passed validation and ColonySim.apply_food_upkeep raised on
+#    state.resources.get(...) against a missing key.
+func flow_missing_resources_backfilled_web() -> void:
+	_stub = {
+		"save_version": 2,
+		"tick": 3,
+		"harvested": {"wood": 1, "stone": 0, "food": 0},
+		"workers": [],
+	}
+	var loaded: Dictionary = _gs.load_game()
+	assert_true(loaded.has("resources"), "web save missing resources is back-filled")
+	assert_true(loaded["resources"] is Dictionary, "back-filled resources is a Dictionary")
+	assert_eq(int(loaded["resources"].get("wood", -1)), 0, "back-filled resources.wood defaults to 0")
+	assert_eq(int(loaded["resources"].get("stone", -1)), 0, "back-filled resources.stone defaults to 0")
+	assert_eq(int(loaded["resources"].get("food", -1)), 0, "back-filled resources.food defaults to 0")
+	assert_eq(int(loaded.get("harvested", {}).get("wood", -1)), 1, "existing harvested values preserved")
+
+# 6) A web save missing state.harvested is back-filled the same way.
+func flow_missing_harvested_backfilled_web() -> void:
+	_stub = {
+		"save_version": 2,
+		"tick": 3,
+		"resources": {"wood": 5, "stone": 2, "food": 1},
+		"workers": [],
+	}
+	var loaded: Dictionary = _gs.load_game()
+	assert_true(loaded.has("harvested"), "web save missing harvested is back-filled")
+	assert_true(loaded["harvested"] is Dictionary, "back-filled harvested is a Dictionary")
+	assert_eq(int(loaded["harvested"].get("wood", -1)), 0, "back-filled harvested.wood defaults to 0")
+	assert_eq(int(loaded["harvested"].get("stone", -1)), 0, "back-filled harvested.stone defaults to 0")
+	assert_eq(int(loaded["harvested"].get("food", -1)), 0, "back-filled harvested.food defaults to 0")
+	assert_eq(int(loaded.get("resources", {}).get("wood", -1)), 5, "existing resources values preserved")
+
+# 7) Desktop (file) branch: a save file missing state.resources is back-filled
+#    on load (issue #378). The desktop path shares _validate_and_apply_save
+#    with the web path, but the file round-trip is exercised here so a
+#    regression in either branch is caught.
+func flow_missing_resources_backfilled_desktop() -> void:
+	_gs.use_local_storage = false
+	var path := "user://test_missing_resources.save"
+	_gs.save_game({
+		"save_version": 2,
+		"tick": 3,
+		"harvested": {"wood": 2, "stone": 0, "food": 0},
+		"workers": [],
+	}, path)
+	var loaded: Dictionary = _gs.load_game(path)
+	assert_true(loaded.has("resources"), "desktop save missing resources is back-filled")
+	assert_true(loaded["resources"] is Dictionary, "desktop back-filled resources is a Dictionary")
+	assert_eq(int(loaded["resources"].get("wood", -1)), 0, "desktop back-filled resources.wood defaults to 0")
+	assert_eq(int(loaded["resources"].get("food", -1)), 0, "desktop back-filled resources.food defaults to 0")
+	assert_eq(int(loaded.get("harvested", {}).get("wood", -1)), 2, "desktop existing harvested values preserved")
+	_remove_save_file(path)
+
+# 8) Desktop (file) branch: a save file missing state.harvested is back-filled.
+func flow_missing_harvested_backfilled_desktop() -> void:
+	_gs.use_local_storage = false
+	var path := "user://test_missing_harvested.save"
+	_gs.save_game({
+		"save_version": 2,
+		"tick": 3,
+		"resources": {"wood": 4, "stone": 1, "food": 2},
+		"workers": [],
+	}, path)
+	var loaded: Dictionary = _gs.load_game(path)
+	assert_true(loaded.has("harvested"), "desktop save missing harvested is back-filled")
+	assert_true(loaded["harvested"] is Dictionary, "desktop back-filled harvested is a Dictionary")
+	assert_eq(int(loaded["harvested"].get("wood", -1)), 0, "desktop back-filled harvested.wood defaults to 0")
+	assert_eq(int(loaded["harvested"].get("food", -1)), 0, "desktop back-filled harvested.food defaults to 0")
+	assert_eq(int(loaded.get("resources", {}).get("wood", -1)), 4, "desktop existing resources values preserved")
+	_remove_save_file(path)
+
+# Helper: remove a temporary save file written by the desktop-branch tests.
+func _remove_save_file(path: String) -> void:
+	if FileAccess.file_exists(path):
+		DirAccess.remove_absolute(ProjectSettings.globalize_path(path))