fix(client): address PR #36 review — 10 items from Hoshe + Tyre

Critical:
- deactivate_insert() now called when selecting non-Insert spoke,
  cancelling with no selection, or pressing Escape while insert is
  active. Fixes simulation staying paused permanently after Insert.

Warnings:
- Checklist conditions with empty id excluded from get_results() and
  get_total_count() — prevents impossible-to-complete checklists.
  Warns at load time when empty-id conditions are found.
- _content_base now checks res://content/ first (exported builds),
  falls back to ../content for editor/dev mode.
- 26 new tests for D-054 functions: _angle_to_octant (8 octants),
  _snap_to_octant_dir (9 cases incl. zero/tiny), _wasd_to_world_dir
  (8 facing/movement combos). New test file: test_input_mapper_facing.gd.

Suggestions:
- Cached get_theme_default_font() in checklist overlay _ready().
- Documented InputMapper → GameState coupling as intentional.
- Documented YAML parser # truncation limitation.
- _insert_active reset on Escape dismiss (Tyre #3).
- SimBridge test mode SetFacing reads action_data.facing instead of
  InputMapper global (Tyre #4).
- Removed dead _facing_to_rotation() from entity_renderer.gd (Tyre #5).
- Fixed 2 failing facing indicator tests to use InputMapper.facing_angle
  instead of GameState.player_facing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/tests/test_input_mapper_facing.gd

@@ -0,0 +1,122 @@
+## D-054 facing and movement tests — _angle_to_octant, _snap_to_octant_dir,
+## _wasd_to_world_dir coverage. All functions are static or use only facing_angle.
+##
+## Spec ref: D-054 (mouse-relative facing), Sprint 10 Completion Proof.
+class_name TestInputMapperFacing
+extends GdUnitTestSuite
+
+
+# -- _angle_to_octant ----------------------------------------------------------
+
+func test_angle_to_octant_east() -> void:
+	assert_str(InputMapper._angle_to_octant(0.0)).is_equal("East")
+
+func test_angle_to_octant_north() -> void:
+	assert_str(InputMapper._angle_to_octant(-PI / 2.0)).is_equal("North")
+
+func test_angle_to_octant_south() -> void:
+	assert_str(InputMapper._angle_to_octant(PI / 2.0)).is_equal("South")
+
+func test_angle_to_octant_west() -> void:
+	assert_str(InputMapper._angle_to_octant(PI)).is_equal("West")
+
+func test_angle_to_octant_northeast() -> void:
+	assert_str(InputMapper._angle_to_octant(-PI / 4.0)).is_equal("Northeast")
+
+func test_angle_to_octant_southeast() -> void:
+	assert_str(InputMapper._angle_to_octant(PI / 4.0)).is_equal("Southeast")
+
+func test_angle_to_octant_southwest() -> void:
+	assert_str(InputMapper._angle_to_octant(3.0 * PI / 4.0)).is_equal("Southwest")
+
+func test_angle_to_octant_northwest() -> void:
+	assert_str(InputMapper._angle_to_octant(-3.0 * PI / 4.0)).is_equal("Northwest")
+
+
+# -- _snap_to_octant_dir -------------------------------------------------------
+
+func test_snap_east() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(1.0, 0.0))).is_equal(Vector2i(1, 0))
+
+func test_snap_north() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(0.0, -1.0))).is_equal(Vector2i(0, -1))
+
+func test_snap_south() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(0.0, 1.0))).is_equal(Vector2i(0, 1))
+
+func test_snap_west() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(-1.0, 0.0))).is_equal(Vector2i(-1, 0))
+
+func test_snap_northeast() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(0.7, -0.7))).is_equal(Vector2i(1, -1))
+
+func test_snap_southwest() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(-0.7, 0.7))).is_equal(Vector2i(-1, 1))
+
+func test_snap_zero_returns_zero() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2.ZERO)).is_equal(Vector2i.ZERO)
+
+func test_snap_tiny_returns_zero() -> void:
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(0.001, 0.0))).is_equal(Vector2i.ZERO)
+
+func test_snap_diagonal_bias() -> void:
+	# Slightly more east than north — should snap to northeast
+	assert_object(InputMapper._snap_to_octant_dir(Vector2(0.8, -0.6))).is_equal(Vector2i(1, -1))
+
+
+# -- _wasd_to_world_dir --------------------------------------------------------
+
+func test_wasd_forward_facing_east() -> void:
+	# W pressed, facing east → move east
+	InputMapper.facing_angle = 0.0  # East
+	var result := InputMapper._wasd_to_world_dir(Vector2i(0, -1))
+	assert_object(result).is_equal(Vector2i(1, 0))
+
+func test_wasd_forward_facing_north() -> void:
+	# W pressed, facing north → move north
+	InputMapper.facing_angle = -PI / 2.0  # North
+	var result := InputMapper._wasd_to_world_dir(Vector2i(0, -1))
+	assert_object(result).is_equal(Vector2i(0, -1))
+
+func test_wasd_backward_facing_north() -> void:
+	# S pressed, facing north → move south
+	InputMapper.facing_angle = -PI / 2.0  # North
+	var result := InputMapper._wasd_to_world_dir(Vector2i(0, 1))
+	assert_object(result).is_equal(Vector2i(0, 1))
+
+func test_wasd_strafe_right_facing_north() -> void:
+	# D pressed, facing north → move east
+	InputMapper.facing_angle = -PI / 2.0  # North
+	var result := InputMapper._wasd_to_world_dir(Vector2i(1, 0))
+	assert_object(result).is_equal(Vector2i(1, 0))
+
+func test_wasd_strafe_left_facing_north() -> void:
+	# A pressed, facing north → move west
+	InputMapper.facing_angle = -PI / 2.0  # North
+	var result := InputMapper._wasd_to_world_dir(Vector2i(-1, 0))
+	assert_object(result).is_equal(Vector2i(-1, 0))
+
+func test_wasd_forward_facing_south() -> void:
+	# W pressed, facing south → move south
+	InputMapper.facing_angle = PI / 2.0  # South
+	var result := InputMapper._wasd_to_world_dir(Vector2i(0, -1))
+	assert_object(result).is_equal(Vector2i(0, 1))
+
+func test_wasd_diagonal_forward_right_facing_east() -> void:
+	# W+D pressed, facing east → move southeast
+	InputMapper.facing_angle = 0.0  # East
+	var result := InputMapper._wasd_to_world_dir(Vector2i(1, -1))
+	assert_object(result).is_equal(Vector2i(1, 1))
+
+func test_wasd_strafe_right_facing_west() -> void:
+	# D pressed, facing west → move north
+	InputMapper.facing_angle = PI  # West
+	var result := InputMapper._wasd_to_world_dir(Vector2i(1, 0))
+	assert_object(result).is_equal(Vector2i(0, -1))
+
+
+func after_test() -> void:
+	# Reset facing to default
+	InputMapper.facing_angle = -PI / 2.0
+	InputMapper.facing_octant = "North"
+	InputMapper._last_sent_octant = "North"