feat: strengthen water and foreground silhouettes

- Upgrade river shader with multi-layer UV flow, fresnel edges, foam highlights, and specular sparkle
- Upgrade waterfall shader with dual-band scrolling, distinct foam contrast, and rim transparency
- Widen river (8m) and waterfall (8m) for greater visual presence
- Increase waterfall mist particles to 72 with wider spread and longer lifetime
- Add fortress crenellations (10), three turrets, and prominent ridge banner for readable skyline silhouette
- Remove duplicate banner nodes from JajceWorld instance (now owned by FortressBlockout scene)
- Update BUILD_IN_PUBLIC_PLAN and LEARNING_ROADMAP to reflect completion

world/jajce/materials/waterfall.gdshader

@@ -1,7 +1,12 @@
 shader_type spatial;
 render_mode blend_mix, depth_draw_opaque, cull_back, diffuse_burley, specular_schlick_ggx;
 
-uniform float scroll_speed : hint_range(0.0, 5.0) = 2.0;
+uniform float scroll_speed : hint_range(0.0, 5.0) = 1.8;
+uniform vec3 deep_color : source_color = vec3(0.1, 0.45, 0.55);
+uniform vec3 mid_color : source_color = vec3(0.45, 0.78, 0.82);
+uniform vec3 foam_color : source_color = vec3(0.9, 0.95, 0.95);
+uniform float foam_contrast : hint_range(0.5, 4.0) = 2.2;
+uniform float sparkle_strength : hint_range(0.0, 0.8) = 0.25;
 
 void vertex() {
 }
@@ -9,13 +14,37 @@ void vertex() {
 void fragment() {
 	vec2 uv = UV;
 	uv.y += TIME * scroll_speed;
-	float pattern = fract(uv.y * 4.0);
-	pattern = smoothstep(0.3, 0.7, pattern);
-	pattern = mix(0.4, 1.0, pattern);
-	vec3 base_color = mix(vec3(0.6, 0.85, 0.9), vec3(1.0, 1.0, 1.0), pattern);
-	ALBEDO = base_color;
-	ALPHA = mix(0.3, 0.7, pattern);
-	EMISSION = vec3(0.36, 0.52, 0.54) * 0.35 * pattern;
-	METALLIC = 0.0;
-	ROUGHNESS = 0.2;
+
+	float band_a = fract(uv.y * 5.0 + sin(uv.x * 2.0) * 0.15);
+	band_a = smoothstep(0.2, 0.55, band_a) * smoothstep(0.8, 0.45, band_a);
+
+	float band_b = fract(uv.y * 3.5 + cos(uv.x * 2.5 + TIME * 0.3) * 0.12);
+	band_b = smoothstep(0.1, 0.5, band_b) * smoothstep(0.85, 0.4, band_b);
+
+	float foam_a = fract(uv.y * 4.0);
+	foam_a = pow(smoothstep(0.0, 0.12, foam_a) * smoothstep(0.3, 0.15, foam_a), foam_contrast);
+
+	float foam_b = fract(uv.y * 6.0 + uv.x * 1.5);
+	foam_b = pow(smoothstep(0.5, 0.58, foam_b) * smoothstep(0.7, 0.6, foam_b), foam_contrast * 0.8);
+
+	float foam = foam_a * 0.7 + foam_b * 0.3;
+
+	vec3 base = mix(deep_color, mid_color, band_a * 0.5 + band_b * 0.3);
+	vec3 color = mix(base, foam_color, foam);
+
+	float sparkle = pow(foam_a, 3.0) * sparkle_strength;
+	float highlight = band_a * band_b * 0.35;
+	float emission_value = sparkle + highlight * 0.3;
+
+	ALBEDO = color;
+	ALPHA = mix(0.25, 0.78, foam * 0.7 + 0.15);
+	EMISSION = color * emission_value;
+	METALLIC = 0.05;
+	ROUGHNESS = 0.15;
+
+	vec3 normal = NORMAL;
+	vec3 view_dir = VIEW;
+	vec3 view_norm = normalize(view_dir);
+	float rim = 1.0 - abs(dot(normal, view_norm));
+	ALPHA = mix(ALPHA, ALPHA * 0.5, rim * 0.6);
 }