WIP: feat(scene) integrate beauty pass — shader water, building blockouts, wind, smoke, 6 textures

- Add 3 missing Terrain3D textures: Dirt Path (id=3), Riverbank Stone (id=4),
  Compacted Ground (id=5) with procedural albedo PNGs + generate tool
- Replace greybox river BoxMesh with animated vertex-displacement water shader
- Replace greybox waterfall BoxMesh with scrolling-UV waterfall shader
- Add WaterfallMist GPUParticles3D with upward drift and alpha fade
- Add wind vertex shader for tree canopies (sin-based, height-weighted sway)
- Replace StylizedTree.tscn with script-driven procedural tree supporting
  3 canopy color variants and position-based randomization
- Replace greybox house boxes with StylizedHouse (walls + pitched roof + door)
- Replace mill box with StylizedMill (body + roof + water wheel cylinder)
- Replace fortress box with FortressBlockout (keep + parapet + corner turret)
- Replace bridge box with BridgeBlockout (deck + pillar supports)
- Add ChimneySmoke GPUParticles3D on each house roof
- Height-snap buildings (fortress + village) to terrain surface in _ready()
- Update JajceWorld.tscn: remove all greybox landmark sub-resources, instance
  new scenes, keep terrain/navigation/sky/fog as-is
- Update scaffold test for new scene structure and beauty elements

tools/generate_terrain_textures.gd

@@ -0,0 +1,59 @@
+@tool
+extends Node
+
+const TEXTURE_DIR := "res://terrain/jajce/textures"
+
+func _ready() -> void:
+	if not Engine.is_editor_hint():
+		return
+	call_deferred("generate")
+
+func generate() -> void:
+	var dir := DirAccess.open(TEXTURE_DIR)
+	if not dir:
+		DirAccess.make_dir_recursive_absolute(ProjectSettings.globalize_path(TEXTURE_DIR))
+
+	_generate_texture("dirt_path_albedo.png", Color("#8b7355"), Color("#c4a882"), 101)
+	_generate_texture("riverbank_stone_albedo.png", Color("#5a6b7a"), Color("#8a9baa"), 102)
+	_generate_texture("compacted_ground_albedo.png", Color("#a0845c"), Color("#d4b896"), 103)
+
+	print("[TerrainTextureGenerator] Generated 3 terrain textures")
+
+func _generate_texture(file_name: String, dark: Color, light: Color, seed_val: int) -> void:
+	seed(seed_val)
+	var grid_size := 16
+	var grid: Array[float] = []
+	grid.resize(grid_size * grid_size)
+	for i in grid_size * grid_size:
+		grid[i] = float(randi() % 1000) / 1000.0
+
+	var image := Image.create_empty(256, 256, false, Image.FORMAT_RGBA8)
+	var cells := grid_size - 1
+	for y in 256:
+		var gyf := float(y) / 256.0 * cells
+		var gy := clampi(gyf, 0, cells)
+		var fy := gyf - gy
+		var gy1 := mini(gy + 1, cells)
+		for x in 256:
+			var gxf := float(x) / 256.0 * cells
+			var gx := clampi(gxf, 0, cells)
+			var fx := gxf - gx
+			var gx1 := mini(gx + 1, cells)
+
+			var v00 := grid[gy * grid_size + gx]
+			var v10 := grid[gy * grid_size + gx1]
+			var v01 := grid[gy1 * grid_size + gx]
+			var v11 := grid[gy1 * grid_size + gx1]
+
+			var vx0 := lerpf(v00, v10, fx)
+			var vx1 := lerpf(v01, v11, fx)
+			var value := lerpf(vx0, vx1, fy)
+
+			var color := dark.lerp(light, value)
+			color.a = 1.0
+			image.set_pixel(x, y, color)
+
+	image.generate_mipmaps()
+	var err := image.save_png(TEXTURE_DIR.path_join(file_name))
+	if err != OK:
+		push_error("Failed to save texture: ", file_name, " error: ", err)

tools/generate_terrain_textures.gd.uid

@@ -0,0 +1 @@
+uid://cl44oi3wmehue