Add self-heating visualisation

src/py_dvt_ate/app/dashboard/app.py

@@ -89,6 +89,68 @@ def display_thermal_chart() -> None:
     )
 
 
+def display_self_heating_panel() -> None:
+    """Display self-heating demonstration panel."""
+    engine: PhysicsEngine = st.session_state.engine
+    history: SimulationHistory = st.session_state.history
+
+    thermal = engine.get_thermal_state()
+    electrical = engine.get_electrical_state()
+
+    # Calculate temperature rises
+    delta_t_jc = thermal.junction_temperature - thermal.case_temperature
+    delta_t_ca = thermal.case_temperature - thermal.chamber_temperature
+
+    col1, col2 = st.columns(2)
+
+    with col1:
+        st.markdown("#### Self-Heating Analysis")
+
+        # Display thermal resistance info
+        st.markdown(
+            f"""
+            | Parameter | Value |
+            |-----------|-------|
+            | Junction-Case Rise (ΔT_jc) | **{delta_t_jc:.2f} °C** |
+            | Case-Ambient Rise (ΔT_ca) | **{delta_t_ca:.2f} °C** |
+            | Power Dissipation | {electrical.power_dissipation * 1000:.1f} mW |
+            | θ_jc (junction-case) | 15 °C/W |
+            | θ_ca (case-ambient) | 5 °C/W |
+            """
+        )
+
+        st.markdown(
+            """
+            **Thermal Coupling:** The junction temperature rises above the case
+            temperature due to power dissipation. This is governed by:
+
+            `T_junction = T_case + P_diss × θ_jc`
+
+            Try increasing the load current or input voltage to see
+            self-heating effects!
+            """
+        )
+
+    with col2:
+        st.markdown("#### Power Dissipation")
+
+        if len(history.time) < 2:
+            st.info("Start the simulation to see power data")
+            return
+
+        power_data = {
+            "Time (s)": list(history.time),
+            "Power (mW)": [p * 1000 for p in history.power_dissipation],
+        }
+
+        st.line_chart(
+            power_data,
+            x="Time (s)",
+            y="Power (mW)",
+            color="#2ca02c",
+        )
+
+
 def display_current_state() -> None:
     """Display current simulation state metrics."""
     engine: PhysicsEngine = st.session_state.engine
@@ -222,6 +284,10 @@ def main() -> None:
     st.subheader("Temperature History")
     display_thermal_chart()
 
+    # Self-heating demonstration
+    st.subheader("Self-Heating Demonstration")
+    display_self_heating_panel()
+
     # Auto-refresh when running
     if st.session_state.running:
         step_simulation(steps=10)