Re-add WorldOverlayRenderer using OrderedSubmitNodeCollector.submitShapeOutline

MC 26.2 removed MultiBufferSource; new in-world outline drawing goes through
OrderedSubmitNodeCollector#submitShapeOutline (PoseStack, VoxelShape,
RenderType, color, width, beforeTranslucent).

- LevelRenderEvents.AFTER_TRANSLUCENT_FEATURES is the new entry point (was
  WorldRenderEvents.AFTER_ENTITIES).
- Friend dots: small 0.3-unit voxel cube above player head, green.
- Markers: 1x1x1 cube outline + thin tall beam (0.1x50x0.1), magenta.
- Camera.position() returns Vector3fc; camera offset applied to render in
  camera-relative space.
- Casts SubmitNodeCollector to OrderedSubmitNodeCollector; if vanilla wraps
  it differently we'll see in the next CI cycle.

src/client/java/ru/nevetime/clientirc/ClientIrcMod.java

@@ -40,6 +40,7 @@ public final class ClientIrcMod implements ClientModInitializer {
         service = new IrcService(config, LOGGER);
 
         OverlayHud.init();
+        WorldOverlayRenderer.init();
         MiddleClickHandler.init(() -> service, () -> resolvePlayerName(Minecraft.getInstance()));
 
         ClientLifecycleEvents.CLIENT_STARTED.register(client -> {

src/client/java/ru/nevetime/clientirc/WorldOverlayRenderer.java

@@ -0,0 +1,78 @@
+package ru.nevetime.clientirc;
+
+import com.mojang.authlib.GameProfile;
+import com.mojang.blaze3d.vertex.PoseStack;
+import net.fabricmc.fabric.api.client.rendering.v1.level.LevelRenderContext;
+import net.fabricmc.fabric.api.client.rendering.v1.level.LevelRenderEvents;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.OrderedSubmitNodeCollector;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.renderer.SubmitNodeCollector;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.phys.shapes.Shapes;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import org.joml.Vector3fc;
+
+public final class WorldOverlayRenderer {
+    private static final int FRIEND_COLOR = 0xFF33FF55;
+    private static final int MARKER_COLOR = 0xFFFF55FF;
+    private static final float OUTLINE_WIDTH = 2.0f;
+    private static final double BEAM_HEIGHT = 50.0;
+
+    private WorldOverlayRenderer() {}
+
+    public static void init() {
+        LevelRenderEvents.AFTER_TRANSLUCENT_FEATURES.register(WorldOverlayRenderer::onRender);
+    }
+
+    private static void onRender(LevelRenderContext context) {
+        Minecraft mc = Minecraft.getInstance();
+        if (mc.level == null || mc.player == null) return;
+
+        SubmitNodeCollector base = context.submitNodeCollector();
+        if (!(base instanceof OrderedSubmitNodeCollector collector)) return;
+
+        PoseStack pose = context.poseStack();
+        Vector3fc camPos = mc.gameRenderer.mainCamera().position();
+        double cx = camPos.x();
+        double cy = camPos.y();
+        double cz = camPos.z();
+
+        for (Player player : mc.level.players()) {
+            if (player == mc.player) continue;
+            GameProfile profile = player.getGameProfile();
+            if (profile == null) continue;
+            if (!FriendsManager.isFriend(profile.name())) continue;
+
+            double px = player.getX() - cx;
+            double py = player.getY() + player.getBbHeight() + 0.3 - cy;
+            double pz = player.getZ() - cz;
+
+            pose.pushPose();
+            pose.translate(px - 0.15, py - 0.15, pz - 0.15);
+            VoxelShape dot = Shapes.box(0.0, 0.0, 0.0, 0.3, 0.3, 0.3);
+            collector.submitShapeOutline(pose, dot, RenderType.lines(), FRIEND_COLOR, OUTLINE_WIDTH, false);
+            pose.popPose();
+        }
+
+        String currentDim = mc.level.dimension().identifier().toString();
+        for (MarkerManager.Marker marker : MarkerManager.active()) {
+            if (!currentDim.equals(marker.dimensionId())) continue;
+
+            double mx = marker.x() - cx;
+            double my = marker.y() - cy;
+            double mz = marker.z() - cz;
+
+            pose.pushPose();
+            pose.translate(mx - 0.5, my, mz - 0.5);
+            collector.submitShapeOutline(pose, Shapes.block(), RenderType.lines(), MARKER_COLOR, OUTLINE_WIDTH, false);
+            pose.popPose();
+
+            pose.pushPose();
+            pose.translate(mx - 0.05, my, mz - 0.05);
+            VoxelShape beam = Shapes.box(0.0, 0.0, 0.0, 0.1, BEAM_HEIGHT, 0.1);
+            collector.submitShapeOutline(pose, beam, RenderType.lines(), MARKER_COLOR, OUTLINE_WIDTH, false);
+            pose.popPose();
+        }
+    }
+}