fix(client): address PR #78 review comments

- Widen world_seed entropy from u32 to full u64 by combining two randi()
  calls (Hoshe warning #1)
- Persist world_seed to save directory and restore on resume_game() so
  loaded sessions maintain D-010 deterministic replay (Tyre warning #2)
- Constrain EntanglementConfig intrigue range based on flat value so
  mundane_ratio stays within D-029 spec [45,55]% (both reviewers)
- Remove dead VIS_PERIPHERAL constant and _grow_bounds() method
- Update test_client_p1 peripheral test for forward-only simplification
- Fix misleading exp_fade shader comment (filter_nearest = hard step)

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

client/scripts/autoloads/fog_state.gd

@@ -8,7 +8,6 @@ extends Node
 # Used by fog shader to distinguish visual treatment per tile.
 # Test assertions reference these: assert_that(byte).is_equal(FogState.VIS_FORWARD)
 const VIS_HIDDEN: int = 0        # Not in LOS — fully fogged
-const VIS_PERIPHERAL: int = 180  # In LOS, peripheral sector — light fog dimming
 const VIS_FORWARD: int = 255     # In LOS, forward sector — clear vision
 
 const EXP_UNEXPLORED: int = 0   # Never seen — total darkness
@@ -139,8 +138,6 @@ func update_from_state() -> void:
 
 func _grow_bounds_from_positions(positions: Dictionary) -> Rect2i:
 	## Compute bounds from visible_positions (Dictionary[Vector2i, bool]).
-	## Equivalent to _grow_bounds() but reads from the always-populated
-	## positions dict instead of the legacy visible_tiles Array.
 	var min_x := 999999
 	var min_y := 999999
 	var max_x := -999999
@@ -158,30 +155,3 @@ func _grow_bounds_from_positions(positions: Dictionary) -> Rect2i:
 	return map_bounds.merge(tile_bounds)
 
 
-func _grow_bounds(tiles: Array) -> Rect2i:
-	## Compute bounds that include all currently visible tiles, merged with
-	## existing bounds so the texture only grows — never shrinks. Explored
-	## tiles always stay within bounds and render as deep fog, not black.
-	var min_x := 999999
-	var min_y := 999999
-	var max_x := -999999
-	var max_y := -999999
-	for tile in tiles:
-		if not tile is Dictionary or not tile.has("x") or not tile.has("y"):
-			continue
-		min_x = mini(min_x, int(tile.x))
-		min_y = mini(min_y, int(tile.y))
-		max_x = maxi(max_x, int(tile.x))
-		max_y = maxi(max_y, int(tile.y))
-	# Guard: all tiles invalid (no x/y) — sentinels would produce negative Rect2i
-	if min_x > max_x:
-		return map_bounds
-	# Margin for fog gradient bleed at edges.
-	# The Gaussian blur in fog.gdshader samples at 2-texel intervals across a 7x7 kernel,
-	# reaching ±6 tiles from the fragment position. Margin must be >= 8 to avoid
-	# clamping artifacts at texture boundaries.
-	var tile_bounds := Rect2i(min_x - 8, min_y - 8, max_x - min_x + 17, max_y - min_y + 17)
-	# Merge with existing bounds — grow only
-	if map_bounds.size.x <= 1 and map_bounds.size.y <= 1:
-		return tile_bounds
-	return map_bounds.merge(tile_bounds)

client/scripts/autoloads/session_manager.gd

@@ -33,16 +33,23 @@ func new_game() -> String:
 	GameState.current_game_id = game_id
 
 	# #175: Generate world_seed for deterministic simulation (D-010, D-029).
-	# Uses randi() (u32) for a seed that maps cleanly to Rust u64 via MessagePack.
-	# 4 billion seeds is sufficient entropy for EntanglementConfig variation (D-029).
-	GameState.world_seed = rng.randi()
+	# Combines two randi() calls (u32 each) into full u64 entropy range.
+	# Without this, upper 32 bits are always zero — halving the seed space.
+	GameState.world_seed = (rng.randi() << 32) | rng.randi()
+
+	# Persist world_seed to save directory so resume_game() can restore it.
+	# Without this, loaded sessions would send seed=0, breaking D-010 determinism.
+	_write_seed_file(save_path, GameState.world_seed)
 
 	return game_id
 
 
 ## Resume an existing game session by setting the active game-id.
+## Restores world_seed from the save directory for D-010 deterministic replay.
 func resume_game(game_id: String) -> void:
 	GameState.current_game_id = game_id
+	var save_path := SAVES_DIR + game_id + "/"
+	GameState.world_seed = _read_seed_file(save_path)
 
 
 ## List all game directories under user://saves/ sorted by last-modified (most recent first).
@@ -117,6 +124,24 @@ func _cleanup_quit_dialog() -> void:
 	_quit_dialog = null
 
 
+## Write world_seed to a file in the save directory for session persistence.
+func _write_seed_file(save_path: String, seed: int) -> void:
+	var file := FileAccess.open(save_path + "world_seed", FileAccess.WRITE)
+	if file == null:
+		push_error("SessionManager: failed to write seed file: %s" % error_string(FileAccess.get_open_error()))
+		return
+	file.store_64(seed)
+
+
+## Read world_seed from save directory. Returns 0 if file missing (legacy saves).
+func _read_seed_file(save_path: String) -> int:
+	var file := FileAccess.open(save_path + "world_seed", FileAccess.READ)
+	if file == null:
+		push_warning("SessionManager: no seed file in %s — using seed=0 (legacy save)" % save_path)
+		return 0
+	return file.get_64()
+
+
 func _find_newest_save(dir_path: String) -> String:
 	var dir := DirAccess.open(dir_path)
 	if dir == null: