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/water.gdshader

@@ -1,20 +1,54 @@
 shader_type spatial;
 render_mode blend_mix, depth_draw_opaque, cull_back, diffuse_burley, specular_schlick_ggx;
 
-uniform float wave_strength : hint_range(0.0, 1.0) = 0.15;
-uniform float wave_speed : hint_range(0.0, 5.0) = 1.2;
+uniform float wave_strength : hint_range(0.0, 0.5) = 0.08;
+uniform float wave_speed : hint_range(0.0, 5.0) = 0.8;
+uniform float flow_speed : hint_range(0.0, 3.0) = 0.6;
+uniform vec3 deep_color : source_color = vec3(0.06, 0.24, 0.38);
+uniform vec3 shallow_color : source_color = vec3(0.18, 0.44, 0.58);
+uniform vec3 foam_color : source_color = vec3(0.82, 0.88, 0.86);
+uniform float rim_power : hint_range(0.5, 5.0) = 2.5;
+uniform float sparkle_strength : hint_range(0.0, 1.0) = 0.12;
+
+global uniform vec3 sun_direction = vec3(0.4, 0.8, 0.4);
 
 void vertex() {
 	vec3 pos = VERTEX;
-	float wave = sin(pos.z * 0.4 + TIME * wave_speed) * wave_strength;
-	pos.y += wave;
+	float wave_a = sin(pos.x * 0.35 + pos.z * 0.25 + TIME * wave_speed) * wave_strength;
+	float wave_b = cos(pos.x * 0.45 - pos.z * 0.55 + TIME * wave_speed * 0.7) * wave_strength * 0.6;
+	float wave_c = sin(pos.z * 0.7 + TIME * wave_speed * 1.3) * wave_strength * 0.35;
+	pos.y += wave_a + wave_b + wave_c;
 	VERTEX = pos;
 }
 
 void fragment() {
-	ALBEDO = vec3(0.12, 0.39, 0.55);
-	METALLIC = 0.15;
-	ROUGHNESS = 0.1;
-	EMISSION = vec3(0.05, 0.19, 0.24) * 0.45;
-	ALPHA = 0.72;
+	vec3 view_dir = VIEW;
+	vec3 normal = NORMAL;
+	vec3 view_norm = normalize(view_dir);
+
+	float rim = 1.0 - abs(dot(normal, view_norm));
+	rim = pow(rim, rim_power);
+	rim = smoothstep(0.15, 0.7, rim);
+
+	vec2 uv = UV;
+	uv.x += TIME * flow_speed * 0.4;
+	uv.y += TIME * flow_speed * 0.3;
+	float flow_a = sin(uv.x * 8.0 + uv.y * 5.0) * 0.5 + 0.5;
+	float flow_b = cos(uv.y * 6.0 - uv.x * 4.0 + TIME * 0.25) * 0.5 + 0.5;
+	float flow = mix(flow_a, flow_b, 0.5);
+
+	vec3 water_color = mix(deep_color, shallow_color, flow * 0.6 + 0.2);
+	water_color = mix(water_color, foam_color, rim * 0.65);
+
+	vec3 half_vec = normalize(view_norm + normalize(sun_direction));
+	float specular = pow(max(dot(normal, half_vec), 0.0), 120.0);
+	specular *= smoothstep(0.4, 0.85, rim);
+	float sparkle = specular * sparkle_strength;
+
+	ALBEDO = water_color;
+	METALLIC = 0.08;
+	ROUGHNESS = 0.22;
+	EMISSION = water_color * 0.04 + foam_color * sparkle;
+	ALPHA = 0.76;
+	ALPHA_SCISSOR_THRESHOLD = 0.0;
 }