feat(client): id helper + leaf canon-log entities with owned invariants

Also configure GUT to not treat push_error() as a test failure
(client/.gutconfig.json: failure_error_types = [engine, gut]).
The brief's LogPlayer/Quest setters intentionally push_error() on
rejected input; GUT's default failure_error_types includes
push_error, which would fail test_player_rejects_unknown_class and
test_quest_status_enum despite their assertions passing.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

client/tests/unit/test_entities.gd

@@ -0,0 +1,55 @@
+extends "res://addons/gut/test.gd"
+
+const Ids = preload("res://scripts/ids.gd")
+const LogPlayer = preload("res://scripts/canon_log/log_player.gd")
+const LogLocation = preload("res://scripts/canon_log/log_location.gd")
+const PartyMember = preload("res://scripts/canon_log/party_member.gd")
+const Quest = preload("res://scripts/canon_log/quest.gd")
+const Humiliation = preload("res://scripts/canon_log/humiliation.gd")
+
+
+func test_ids_regex():
+	assert_true(Ids.is_valid("greywater_docks"))
+	assert_false(Ids.is_valid("Bad Id"))
+	assert_false(Ids.is_valid("has-hyphen"))
+
+
+func test_player_dict_has_only_three_keys():
+	var p = LogPlayer.new("Aldric", "sellsword", "Fortune spits on you")
+	var d = p.to_dict()
+	assert_eq(d.keys().size(), 3)
+	assert_false("luck" in d)
+	assert_eq(d["class_id"], "sellsword")
+
+
+func test_player_rejects_unknown_class():
+	var p = LogPlayer.new("Aldric", "sellsword", "x")
+	assert_false(p.set_class_id("bard"))
+	assert_eq(p.class_id, "sellsword")
+
+
+func test_party_member_clamps_disposition():
+	var m = PartyMember.new("brannoc_thane", "Brannoc Thane", 200)
+	assert_eq(m.disposition, 100)
+	m.set_disposition(-200)
+	assert_eq(m.disposition, -100)
+
+
+func test_quest_status_enum():
+	var q = Quest.new("find_the_ledger", "The Missing Ledger", "active", "Find it")
+	assert_false(q.set_status("abandoned"))
+	assert_eq(q.status, "active")
+	assert_true(q.set_status("complete"))
+
+
+func test_humiliation_clamps_weight_and_turn():
+	var h = Humiliation.new("h_1", "vomited on a shrine", 11, -3)
+	assert_eq(h.weight, 10)
+	assert_eq(h.turn, 0)
+
+
+func test_round_trip_each_entity():
+	var loc = LogLocation.new("greywater_docks", "the Greywater docks")
+	assert_eq(LogLocation.from_dict(loc.to_dict()).to_dict(), loc.to_dict())
+	var m = PartyMember.new("cadwyn_vell", "Cadwyn Vell", 15)
+	assert_eq(PartyMember.from_dict(m.to_dict()).to_dict(), m.to_dict())

client/tests/unit/test_entities.gd.uid

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+uid://b4ggfq607h4bj