Release 0.2.0: device-aware controls, spear, settings, shaders

Show touch controls only on touch platforms and keyboard hints only on
desktop, via a shared Controls.use_touch_ui() gate (is_touchscreen_available
is unreliable with emulate_touch_from_mouse). Bumps version to 0.2.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

damage_vignette.gdshader

@@ -0,0 +1,16 @@
+shader_type canvas_item;
+
+// Faint red gradient hugging the screen edges, flashed on a hit. `flash` is tweened
+// 0.9 → 0 by the HUD; the vignette is transparent in the centre and reddens toward
+// the corners so the middle of the screen stays clear.
+uniform float flash : hint_range(0.0, 1.0) = 0.0;
+uniform vec3 tint : source_color = vec3(0.75, 0.0, 0.0);
+uniform float inner : hint_range(0.0, 1.0) = 0.45;
+uniform float outer : hint_range(0.0, 1.0) = 1.0;
+
+void fragment() {
+	// Distance from centre normalised so the corners land at ~1.0.
+	float dist = length(UV - vec2(0.5)) / 0.70710678;
+	float v = smoothstep(inner, outer, dist);
+	COLOR = vec4(tint, v * flash);
+}