fix(client): address PR #25 review — 5 critical bugs, 4 warnings, 3 suggestions

Critical fixes:
- hide_dialogue() sent PAUSE instead of UNPAUSE, permanently freezing
  simulation after every dialogue (both reviewers)
- Confrontation monologue hardcoded in GDScript constant, violating
  D-042/D-020 — moved to ui-strings.yaml as dialogue.confrontation_beat
- Walk-away WASD didn't call set_input_as_handled(), letting movement
  event propagate and potentially stepping on the same frame
- is_dialogue_active() returned _is_showing only — interaction list
  could flash during 300ms fade gap. Now includes dialogue_active state
- Removed dead _last_dialogue_id / get_dialogue_id() state (never read)

Warnings addressed:
- Audio registry now scans res://audio/ recursively (subdirs registered)
- add_bus_effect guarded against duplicate calls in tests
- int64 encoder dead code tagged KNOWN-DEFECT, filed as ticket #516
- D-073 zone crossfade stub comment clarifies Sprint 9+ deferral
- listening_focus dip documents caller tick-gate responsibility (D-069/D-071)

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

client/scripts/autoloads/audio_manager.gd

@@ -15,6 +15,8 @@ const BUSES := [BUS_MUSIC, BUS_AMBIENT, BUS_WORLD_SFX, BUS_PLAYER_ACTIONS, BUS_U
 
 # D-069: Audio dip profiles — dB offsets relative to player slider setting.
 # Mid-range of spec values used (e.g. -6 to -8 → -7).
+# NOTE: listening_focus requires 30+ stationary ticks before activation (D-069/D-071).
+# The tick gate is the caller's responsibility — AudioManager only manages bus volumes.
 const DIP_SPECS := {
 	"dialogue": {
 		"ease_in": 0.3, "ease_out": 0.5,
@@ -70,8 +72,9 @@ func _setup_buses() -> void:
 		_bus_volumes[bus_name] = 0.0
 	# Low-pass filter on Ambient bus — cutoff starts high (bypassed).
 	# Confrontation dip sweeps it down to 800 Hz (D-069).
+	# Guard: skip if filter already exists (e.g. duplicate _ready in tests).
 	var amb_idx := AudioServer.get_bus_index(BUS_AMBIENT)
-	if amb_idx >= 0:
+	if amb_idx >= 0 and _ambient_filter == null:
 		_ambient_filter = AudioEffectLowPassFilter.new()
 		_ambient_filter.cutoff_hz = FILTER_CUTOFF_DEFAULT
 		AudioServer.add_bus_effect(amb_idx, _ambient_filter)
@@ -80,20 +83,28 @@ func _setup_buses() -> void:
 # --- Asset registry (D-068 directory-scan pattern) ---
 
 func _scan_registry() -> void:
-	var dir := DirAccess.open("res://audio/")
+	_scan_dir("res://audio/")
+	print("AudioManager: %d assets registered" % _registry.size())
+
+
+func _scan_dir(path: String) -> void:
+	var dir := DirAccess.open(path)
 	if dir == null:
-		print("AudioManager: res://audio/ not found — all play methods no-op")
+		if path == "res://audio/":
+			print("AudioManager: res://audio/ not found — all play methods no-op")
 		return
 	dir.list_dir_begin()
 	var file_name := dir.get_next()
 	while file_name != "":
-		if not dir.current_is_dir() and not file_name.ends_with(".import"):
+		var full_path := path.path_join(file_name)
+		if dir.current_is_dir():
+			_scan_dir(full_path)
+		elif not file_name.ends_with(".import"):
 			if file_name.get_extension().to_lower() in ["ogg", "wav", "mp3"]:
-				var stream := load("res://audio/" + file_name) as AudioStream
+				var stream := load(full_path) as AudioStream
 				if stream:
 					_registry[file_name.get_basename()] = stream
 		file_name = dir.get_next()
-	print("AudioManager: %d assets registered" % _registry.size())
 
 
 func has_asset(asset_key: String) -> bool:
@@ -268,7 +279,8 @@ func get_volume(bus: String) -> float:
 # --- Zone crossfade (D-073 stub) ---
 
 ## Handle zone transition. Server sends zone_id per tile in ObserverSnapshot.
-## Full crossfade implementation deferred — stub for integration point.
+## Full crossfade implementation deferred to Sprint 9+ (D-073).
+## Stub exists so server integration can call it without conditional checks.
 func set_zone(_zone_id: String) -> void:
 	pass
 

client/scripts/main.gd

@@ -13,10 +13,6 @@ extends Node2D
 @onready var stance_indicator = $UILayer/StanceIndicator  # D-053: z-layer 7
 @onready var cursor_renderer = $UILayer/CursorRenderer  # D-056: z-layer 7
 
-# Tracks the dialogue_id from dialogue_box to prevent consume-once race during fade-in.
-# If a new snapshot arrives with null dialogue while fade-in is still running,
-# we don't re-trigger show_dialogue because _last_dialogue_id still matches.
-var _last_dialogue_id: int = 0
 var _last_dialogue_npc_id: int = -1  # D-064: NPC entity_id for WalkAway input
 var _camera_anchored: bool = false
 var _last_monologue_tick: int = -1  # Prevent re-consuming monologue when same tick polled twice
@@ -169,7 +165,6 @@ func _consume_dialogue() -> void:
 		dlg.get("speech", ""),
 		dlg.get("options", [])
 	)
-	_last_dialogue_id = dialogue_box.get_dialogue_id()
 	GameState.current_dialogue = null