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/index.html

@@ -154,6 +154,10 @@
         fill="url(#fg-yellow)"/>
     </g>
 
+    <!-- Power soll label (below flame area, updated by JS) -->
+    <text id="svg-power-soll" x="120" y="244" font-size="10"
+          fill="#ffe0b2" text-anchor="middle" dominant-baseline="auto"></text>
+
     <!-- Water fill (behind pot walls) -->
     <rect id="water-fill" x="63" y="172" width="114" height="0"
           fill="#1a4a72" clip-path="url(#pot-clip)"/>
@@ -229,6 +233,9 @@
     <rect x="106" y="2"  width="28" height="20" fill="#333" rx="3"/>
     <rect x="110" y="6"  width="10" height="8"  fill="#4a4a4a" rx="1"/>
     <circle cx="129" cy="11" r="3" fill="#cc2222"/>
+    <!-- Stirrer RPM label (updated by JS) -->
+    <text id="svg-stirrer-rpm" x="137" y="12" font-size="9"
+          fill="#9e9e9e" text-anchor="start" dominant-baseline="middle"></text>
 
     <!-- Thermometer tube -->
     <rect x="212" y="28" width="14" height="146" rx="7"