I consider this to be the most important milestone so far because I’ve connected the visual interface to the electrical logic. Until now, I had the two parts separate, the “brain” (calculations and warnings) and the interface (drag/drop), but now they work together.

What changed:
Each visual component now has a real electrical object associated below it (a Battery, Resistor, or LED).
I implemented a simple grouping algorithm: it goes through all the wires and discovers which components are connected to each other (even indirectly).
Each connected group is passed to the existing logic (SeriesCircuit), which validates and calculates the circuit.
The result appears in a real-time panel in the corner of the screen: voltage, current, power, and status if everything is okay, or a red warning if there is insufficient resistance or excessive current.
In other words, I can now drag a battery, resistor, and LED onto the screen, connect them with wires by clicking on the pins, and immediately see if the circuit is correct, and if not, understand why and how to fix it.