Pulse local spawn ring white→gold for visibility on any terrain

The local player's spawn ring was a static near-white tint, which could
wash out against light backgrounds. Drive the ring color from the
existing breath animation in SpawnOverlayPass so it pulses between
white and gold at 60fps — one end of the pulse always contrasts with
the terrain. Remove the now-unused hardcoded self tint from
WebGLFrameBuilder; the pass owns the self color now.

src/client/WebGLFrameBuilder.ts

@@ -134,12 +134,9 @@ export class WebGLFrameBuilder {
       const spawnTile = p.state.spawnTile;
       if (spawnTile === undefined) continue;
       const isSelf = me !== null && p.smallID() === me.smallID();
-      // myPlayer reads as a near-white with a faint gold/silver tint so the
-      // local-player ring is visually distinct from any team color; everyone
-      // else uses their territory tint.
-      const c = isSelf
-        ? { r: 248, g: 218, b: 140 }
-        : p.territoryColor().toRgb();
+      // myPlayer's ring color is overridden in SpawnOverlayPass (animated
+      // white→gold pulse); everyone else uses their territory tint.
+      const c = p.territoryColor().toRgb();
       centers.push({
         // spawnTile tracks the player's currently-selected spawn directly —
         // updates the same tick the player picks a new location (faster than

src/client/render/gl/passes/SpawnOverlayPass.ts

@@ -150,9 +150,17 @@ export class SpawnOverlayPass {
       const c = this.centers[i];
       dataA[i * 4 + 0] = c.x;
       dataA[i * 4 + 1] = c.y;
-      dataA[i * 4 + 2] = c.r;
-      dataA[i * 4 + 3] = c.g;
-      dataB[i * 4 + 0] = c.b;
+      if (c.isSelf) {
+        // Self ring pulses white (1,1,1) → gold (1,0.84,0) in phase with the
+        // breath so one end of the pulse always contrasts with the terrain.
+        dataA[i * 4 + 2] = 1;
+        dataA[i * 4 + 3] = 1 - 0.16 * breathRadius;
+        dataB[i * 4 + 0] = 1 - breathRadius;
+      } else {
+        dataA[i * 4 + 2] = c.r;
+        dataA[i * 4 + 3] = c.g;
+        dataB[i * 4 + 0] = c.b;
+      }
       dataB[i * 4 + 1] = c.isSelf ? 1 : 0;
       dataB[i * 4 + 2] = c.isTeammate ? 1 : 0;
       dataB[i * 4 + 3] = 0;