Add separate Iron Coast mission, weapon and enemy mods with SD HD artwork and audio

examples/mods/seeker_swarm/scripts/equipment.rhai

@@ -0,0 +1,6 @@
+// Recovery is recorded separately from the weapon firing state.
+fn on_pickup(event, state, random) {
+    let recovered = if state.contains("recovered") { state.recovered % 100000 + 1 } else { 1 };
+    #{ commands: [#{ op: "objective", key: "seeker_swarm:recovered", value: recovered }],
+       state: #{ recovered: recovered } }
+}

examples/mods/seeker_swarm/scripts/weapon.rhai

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+// Built-in homing projectiles handle the normal volley and collision rules.
+// Callbacks add deterministic visuals, audio and serializable weapon counters.
+fn on_fire(event, state, random) {
+    let bursts = if state.contains("bursts") { state.bursts % 100000 + 1 } else { 1 };
+    let hits = if state.contains("hits") { state.hits } else { 0 };
+    let commands = [
+        #{ op: "play_sound", sound: "seeker_swarm:fire" },
+#{ op: "effect", x: event.x, y: event.y - 3 }
+    ];
+    #{ commands: commands, state: #{ bursts: bursts, hits: hits } }
+}
+
+fn on_hit(event, state, random) {
+    let bursts = if state.contains("bursts") { state.bursts } else { 0 };
+    let hits = if state.contains("hits") { state.hits % 100000 + 1 } else { 1 };
+    let commands = [
+        #{ op: "play_sound", sound: "seeker_swarm:impact" },
+        #{ op: "effect", x: event.x, y: event.y }
+    ];
+
+    // A small fragmentation charge affects at most two nearby surviving enemies.
+    let fragments = 0;
+    for enemy in event.entities {
+        if fragments < 2 && enemy.entity != event.entity && enemy.health > 0
+            && abs(enemy.x + enemy.width / 2 - event.x) <= 18
+            && abs(enemy.y + enemy.height / 2 - event.y) <= 18 {
+            commands.push(#{ op: "damage", entity: enemy.entity, amount: 2 });
+            fragments += 1;
+        }
+    }
+    #{ commands: commands, state: #{ bursts: bursts, hits: hits } }
+}