Add mass driver station system with Lagrange point placement

- Lagrange point computation (L1-L5) for any Sun-planet pair in Rust
- Station generation: auto-place at Lagrange points by priority (inner → outer planets)
- Station panel UI: count slider (5-50), launch velocity slider (5-100 km/s) with info tooltip
- Blue diamond markers on 2D canvas with labels when zoomed in
- Active station list in sidebar (Earth L1, Mars L2, Jupiter L4, etc.)
- WASM API: generate_stations(), get_station_positions(), get_station_names()
- Station positions update every frame (co-rotating with planets at Lagrange points)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/lib/render/canvas2d/SolarSystem2D.ts

@@ -17,6 +17,9 @@ export class SolarSystem2DRenderer {
 	private positions: Float64Array = new Float64Array(0);
 	private velocities: Float64Array = new Float64Array(0);
 	private orbitPoints: Map<number, Float64Array> = new Map();
+	private stationPositions: Float64Array = new Float64Array(0);
+	private stationNames: string[] = [];
+	private showStations: boolean = true;
 	private isDragging = false;
 	private lastMouse = { x: 0, y: 0 };
 	private animFrameId: number = 0;
@@ -77,6 +80,12 @@ export class SolarSystem2DRenderer {
 		this.orbitPoints.set(bodyId, points);
 	}
 
+	updateStations(positions: Float64Array, names: string[], visible: boolean) {
+		this.stationPositions = positions;
+		this.stationNames = names;
+		this.showStations = visible;
+	}
+
 	render() {
 		const { canvas, ctx } = this;
 		const dpr = window.devicePixelRatio || 1;
@@ -115,6 +124,15 @@ export class SolarSystem2DRenderer {
 			}
 		}
 
+		// Draw stations
+		if (this.showStations && this.stationPositions.length > 0) {
+			for (let i = 0; i < this.stationNames.length; i++) {
+				const x = this.stationPositions[i * 3];
+				const y = this.stationPositions[i * 3 + 1];
+				this.drawStation(x, y, this.stationNames[i]);
+			}
+		}
+
 		// Scale indicator
 		this.drawScaleBar(rect.width, rect.height);
 	}
@@ -269,6 +287,32 @@ export class SolarSystem2DRenderer {
 		ctx.fillText(info.name, sx + size + 4, sy + 3);
 	}
 
+	private drawStation(xAU: number, yAU: number, name: string) {
+		const ctx = this.ctx;
+		const [sx, sy] = this.auToScreen(xAU, yAU);
+
+		// Diamond shape
+		const s = 3;
+		ctx.fillStyle = 'rgba(74, 158, 255, 0.6)';
+		ctx.strokeStyle = 'rgba(74, 158, 255, 0.8)';
+		ctx.lineWidth = 1;
+		ctx.beginPath();
+		ctx.moveTo(sx, sy - s);
+		ctx.lineTo(sx + s, sy);
+		ctx.lineTo(sx, sy + s);
+		ctx.lineTo(sx - s, sy);
+		ctx.closePath();
+		ctx.fill();
+		ctx.stroke();
+
+		// Label (only show when zoomed in enough)
+		if (this.getScale() > 50) {
+			ctx.fillStyle = 'rgba(74, 158, 255, 0.5)';
+			ctx.font = '8px monospace';
+			ctx.fillText(name, sx + s + 3, sy + 3);
+		}
+	}
+
 	private drawScaleBar(w: number, h: number) {
 		const ctx = this.ctx;
 		const scale = this.getScale();