feat: directional wind breeze and painted-terrain Ghibli styling

- Wind strokes now flow in a single prevailing direction (left-to-right breeze)
  with gentle flatness, narrow spread, and subtle tangential sway
- Added floating white specks (WindSpecks) as sunlight pollen/dust motes
- Two of each emitter (valley + ridge) for layered atmosphere
- Terrain: disabled auto_base_texture for flatter painted look, enabled
  overlay texture, bolder macro-variation (yellow-green 0.78/0.90/0.42
  and emerald 0.55/0.75/0.38), sharper material blends

world/jajce/WindSpecks.tscn

@@ -0,0 +1,37 @@
+[gd_scene load_steps=4 format=3]
+
+[sub_resource type="ParticleProcessMaterial" id="ParticleProcessMaterial_specks"]
+lifetime_randomness = 0.8
+spread = 120.0
+flatness = 0.5
+gravity = Vector3(-0.35, 0.25, 0.0)
+initial_velocity_min = 0.2
+initial_velocity_max = 1.2
+scale_min = 0.06
+scale_max = 0.28
+color = Color(1, 0.98, 0.9, 0.3)
+color_ramp = 1
+emission_shape = 1
+emission_box_extents = Vector3(32.0, 14.0, 32.0)
+
+[sub_resource type="StandardMaterial3D" id="Material_speck"]
+albedo_color = Color(1, 0.98, 0.92, 0.3)
+transparency = 1
+shading_mode = 0
+billboard_mode = 1
+cull_mode = 0
+
+[sub_resource type="QuadMesh" id="Mesh_speck"]
+material = SubResource("Material_speck")
+size = Vector2(0.12, 0.12)
+
+[node name="WindSpecks" type="GPUParticles3D"]
+emitting = true
+amount = 40
+lifetime = 6.0
+one_shot = false
+preprocess = 4.0
+speed_scale = 1.0
+local_coords = false
+process_material = SubResource("ParticleProcessMaterial_specks")
+draw_pass_1 = SubResource("Mesh_speck")