Add power soll and stirrer RPM to pot SVG; tune flame position

- Power soll label centered below flame area (amber, clears when off)
- Stirrer RPM label next to motor housing (clears when stopped)
- Flame base moved 20 units closer to pot bottom
- Drop Ist/Soll LCD header row to save vertical space

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SH2D4LRuCnhLSzoYerAfJX

web/app.js

@@ -332,6 +332,8 @@ function updateStirrerVisualization() {
 		g.classList.remove('spinning');
 		if (particles) particles.classList.remove('stirring');
 	}
+	const rpmLabel = document.getElementById('svg-stirrer-rpm');
+	if (rpmLabel) rpmLabel.textContent = stirrerSpeedIst > 0 ? `${Math.round(stirrerSpeedIst)} rpm` : '';
 }
 
 // --- Fire visualization ---
@@ -347,8 +349,10 @@ function updateFireVisualization() {
 		const minScale  = 1200 / heaterMaxPower;
 		const scale     = Math.max(minScale, intensity);
 		g.style.opacity = '1';
-		g.setAttribute('transform', `translate(0,248) scale(1,${scale.toFixed(3)}) translate(0,-248)`);
+		g.setAttribute('transform', `translate(0,228) scale(1,${scale.toFixed(3)}) translate(0,-248)`);
 	}
+	const powerLabel = document.getElementById('svg-power-soll');
+	if (powerLabel) powerLabel.textContent = heaterPowerSoll > 0 ? `${Math.round(heaterPowerSoll)} W` : '';
 }
 
 // --- Pot visualization ---