vaillant: add RunDataFlowTemp + RunDataReturnTemp to 08.hmu.HW5103

[buliwyf42]

Summary

PR #496 (merged 2025-04-12) added RunDataFlowTemp and RunDataReturnTemp to src/vaillant/08.hmu.tsp. The HW=5103 firmware variant has its own file (08.hmu.HW5103.tsp) that does not import from 08.hmu.tsp, so HW=5103 owners — explicitly the hardware @roe-lz called out in #446 ("These work on MF=Vaillant;ID=HMU00;SW=0902;HW=5103") — never received the new entities.

This adds the two models to 08.hmu.HW5103.tsp so the same telemetry is available on HW=5103 systems.

Live verification (HW=5103;SW=0902)

RunDataFlowTemp   = 31.29 °C
RunDataReturnTemp = 31.05 °C

Both consistent with the existing flowtemp / status01_temp + status01_temp_1 readings within sensor tolerance, but at higher precision because tempv is EXP rather than D1C.

Build

• npx tsp compile --emit @ebusd/ebus-typespec --warn-as-error exits 0
• ebusd --checkconfig with the compiled CSV exits 0

Diff

   @inherit(r_7)
   @ext(0xde, 0x8)
   model RunDataAirInletTemp {
     value: tempv;
   }

+  @inherit(r_7)
+  @ext(0xfc, 0x8)
+  model RunDataFlowTemp {
+    /** current flow temp, accurate to 2 decimal places */
+    value: tempv;
+  }
+
+  @inherit(r_7)
+  @ext(0x6, 0x9)
+  model RunDataReturnTemp {
+    /** current return temp, accurate to 2 decimal places */
+    value: tempv;
+  }
+
   // B516

Same r_7 base, same tempv type, same @ext bytes as the generic 08.hmu.tsp.

[stgm]

@john30 I'd like these two values to be added, too. They work (tested), and are relevant values on the HW5103. One of these I have been actively using.