v1.3.0 — the aquarium gets its art layer

• Painted background plates (dark: deep indigo water; light: sunlit shallows) — seamless-tileable, kept translucent so the UI breathes through
• Token fish are real fish now (not mini whales)
• Seaweed stands root the floor line
• A progress coral grows through four stages as the turn's tool count climbs
• Waiting on approval: a blinking pink buoy bobs at the tank's edge