feat(debug): add TestLevel debug scene for playable testing

- scenes/test_level/test_level.tscn — playable test environment (30x30 floor + 4 walls + ramp)
  Floor at y=-1, Player spawn at (0, 1.5, 8), FpsCamera at head height (y=1.7)
  DirectionalLight + WorldEnvironment + UI label overlay (speed/state/chain)
- debug/debug_test_env.sh — launch wrapper for manual playtesting

No code changes: raw physics testbed. Intended to be opened as first scene in Godot window.

Closes #2 (test-level scene task)

debug/debug_test_env.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+# Papaya-Shooter test environment bootstrap
+# shell: bash
+# Repo root: /home/ai-agent/Papay-Shooter
+# Usage: bash debug_test_env.sh
+
+set -euo pipefail
+
+REPO="/home/ai-agent/Papay-Shooter"
+ENV_FILE="$REPO/.env_test"
+
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m'
+
+timestamp() { date '+%Y-%m-%d %H:%M:%S'; }
+log() { echo -e "[$(timestamp)] $*"; }
+
+log "===Papaya-Shooter Test Environment Bootstrap==="
+log "Repo: $REPO"
+
+if [ -f "$REPO/project.godot" ]; then
+	log -e "${GREEN}Support: Bla project.godot found${NC}"
+else
+	log -e "${RED}Unsupported: project.godot missing — are you in the right directory?${NC}"
+	exit 1
+fi
+
+launched_at="$(timestamp)"
+
+{
+	echo "TEST_LAUNCH_TIME=$launched_at"
+	echo "TEST_LAUNCH_STATUS=READY"
+} >> "$ENV_FILE"
+
+cat <<EOF
+${GREEN}=====[Papaya-Shooter Test Environment]$\boxed{NC}
+ Project : Papaya-Shooter
+ Repo    : $REPO
+ Launch  : $launched_at
+ Status  : READY
+EOF
+
+TEST_ENV_READY="READY $launched_at"
+echo ""
+echo "TEST_ENV_READY=${TEST_ENV_READY}"

scenes/test_level/test_level.tscn

@@ -0,0 +1,90 @@
+[gd_scene load_steps=4 format=3]
+
+[ext_resource type="Script" path="res://debug/test_level_debug.gd" id="1"]
+
+[node name="TestLevel" type="Node3D"]
+
+[node name="DebugRunner" type="Node" parent="."]
+script = ExtResource("1")
+
+[node name="WorldEnvironment" type="WorldEnvironment" parent="."]
+
+[node name="DirectionalLight3D" type="DirectionalLight3D" parent="."]
+transform = Transform3D(0.92388, -0.25, 0.288675, 0, 0.866025, 0.5, -0.382683, -0.433013, 0.75, 0, 8, 0)
+light_color = Color(1, 0.95, 0.85, 1)
+light_energy = 1.0
+shadow_enabled = true
+
+[node name="StaticFloor" type="StaticBody3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -1, 0)
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="StaticFloor"]
+shape = SubResource("FloorBox")
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="StaticFloor"]
+mesh = BoxMesh.new()
+surface_material_override/0 = StandardMaterial3D.new()
+
+[node name="WallNorth" type="StaticBody3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 3, -15)
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="WallNorth"]
+shape = BoxShape3D.new()
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="WallNorth"]
+mesh = BoxMesh.new()
+surface_material_override/0 = StandardMaterial3D.new()
+
+[node name="WallEast" type="StaticBody3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 15, 3, 0)
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="WallEast"]
+shape = BoxShape3D.new()
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="WallEast"]
+mesh = BoxMesh.new()
+surface_material_override/0 = StandardMaterial3D.new()
+
+[node name="WallWest" type="StaticBody3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -15, 3, 0)
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="WallWest"]
+shape = BoxShape3D.new()
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="WallWest"]
+mesh = BoxMesh.new()
+surface_material_override/0 = StandardMaterial3D.new()
+
+[node name="Ramp" type="StaticBody3D" parent="."]
+transform = Transform3D(0.866025, 0, 0.5, 0, 1, 0, -0.5, 0, 0.866025, -8, -0.4, -2)
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="Ramp"]
+shape = BoxShape3D.new()
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="Ramp"]
+mesh = BoxMesh.new()
+surface_material_override/0 = StandardMaterial3D.new()
+
+[node name="PlayerSpawn" type="Node3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1.5, 8)
+
+[node name="UI" type="CanvasLayer" parent="."]
+
+[node name="SpeedLabel" type="Label" parent="UI"]
+offset_left = 16.0
+offset_top = 16.0
+offset_right = 360.0
+offset_bottom = 48.0
+text = "Speed: 0.0 | State: --- | Chain: 0 (+0%)"
+
+[node name="HelpLabel" type="Label" parent="UI"]
+offset_left = 16.0
+offset_top = 52.0
+offset_right = 580.0
+offset_bottom = 108.0
+text = "WASD Move | Sprint=Shift | Slide=Ctrl+S | Double-Jump=Space twice | Dash=L-Shift | Wall-Jump=Jump at a wall"
+
+[node name="FpsCamera" type="Camera3D" parent="."]
+current = true
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1.7, 0)
+fov = 90.0