fix(client): correct 5 bugs found in pre-PR review

- sound_indicator_renderer: draw_colored_polygon → draw_polygon (runtime crash)
- sound_indicator_renderer: append+dedup instead of clear — indicators now
  survive 3.5s instead of dying after one server tick
- dialogue_box: wire Constants.DIALOGUE_MAX_WIDTH (640px) instead of
  hardcoded 832px MAX_WIDTH_PX
- dialogue_box.tscn: update default offsets to ±320 (was ±416)
- decisions/perception.md: fix footer typo (1920px → 640px)
- tests updated for new append/dedup indicator behavior

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

client/scripts/rendering/sound_indicator_renderer.gd

@@ -13,8 +13,9 @@ extends Node2D
 ##   Danger   #d45d5d — alert, gunshot, explosion, threat
 ##
 ## Each indicator lives for INDICATOR_LIFETIME seconds and fades out over
-## the last FADE_DURATION seconds. New events from the same tick replace
-## any previously received events (server sends current medium events per tick).
+## the last FADE_DURATION seconds. New events are appended each tick;
+## expired indicators are removed by _process(). Deduplication prevents
+## the same source position from stacking multiple arrows.
 
 const TILE_SIZE: int = Constants.TILE_SIZE
 
@@ -47,20 +48,32 @@ func _process(delta: float) -> void:
 	queue_redraw()
 
 
-## Update medium-range sound events from snapshot.
+## Append new medium-range sound events from snapshot.
 ## events: Array of {x: float, y: float, event_type: String}
 ## Only Medium range_category events should be passed.
+## Deduplicates by tile position — if an indicator already exists at (x,y),
+## its timer resets instead of spawning a duplicate arrow.
 func update_sound_events(events: Array) -> void:
-	_indicators.clear()
 	for evt in events:
 		if not evt.has("x") or not evt.has("y"):
 			continue
-		_indicators.append({
-			"x": float(evt.x),
-			"y": float(evt.y),
-			"event_type": evt.get("event_type", ""),
-			"elapsed": 0.0,
-		})
+		var ex: float = float(evt.x)
+		var ey: float = float(evt.y)
+		# Deduplicate: reset timer if an indicator already exists at this tile
+		var found := false
+		for ind in _indicators:
+			if is_equal_approx(ind.x, ex) and is_equal_approx(ind.y, ey):
+				ind.elapsed = 0.0
+				ind.event_type = evt.get("event_type", "")
+				found = true
+				break
+		if not found:
+			_indicators.append({
+				"x": ex,
+				"y": ey,
+				"event_type": evt.get("event_type", ""),
+				"elapsed": 0.0,
+			})
 	if not _indicators.is_empty():
 		queue_redraw()
 
@@ -122,7 +135,7 @@ func _rect_edge_point(center: Vector2, dir: Vector2, half: Vector2, inset: float
 func _draw_arrow(pos: Vector2, dir: Vector2, color: Color) -> void:
 	var perp := Vector2(-dir.y, dir.x)
 	var base_center := pos - dir * ARROW_LEN
-	draw_colored_polygon(
+	draw_polygon(
 		PackedVector2Array([pos, base_center - perp * ARROW_HALF, base_center + perp * ARROW_HALF]),
 		PackedColorArray([color, color, color])
 	)