Subcircuit file saved as .kicad_sch in eSim 2.5 (KiCad 6) not recognized by "Edit Subcircuit" option

[OfficialVarad]

Description

In eSim 2.5, when creating a subcircuit, the schematic file is automatically saved with the extension .kicad_sch instead of .sch. Because of this, the "Edit Subcircuit" option does not detect the existing subcircuit and keeps asking to create a new one. As a result, users cannot edit subcircuits and final simulation fails due to missing subcircuit linkage.

This issue appears due to incompatibility with KiCad 6, which uses .kicad_sch by default, while eSim still expects .sch.

Steps to Reproduce

1. Open eSim 2.5 and create a new project.
2. Click New Subcircuit Schematic.
3. When prompted to create the schematic, click Yes.
4. The subcircuit is created and saved.
5. Now click Edit Subcircuit Schematic for the same subcircuit.
6. eSim again prompts to create a new schematic even though one already exists.

eSim should detect and open the previously created subcircuit file.
Subcircuit schematic should be saved in .sch format or .kicad_sch should be supported by the editor.

Screenshots

The issue occurs because the subcircuit file is saved as .kicad_sch, which is not readable by the Edit Subcircuit function.

• Version and OS
• eSim Version: 2.5
• KiCad Version: 6.x
• OS: Windows 10 (64-bit)

Additional Context
This issue breaks subcircuit creation workflow and prevents eSim 2.5 from working properly with KiCad 6. Need to add complete support for .kicad_sch files or automatically rename them to .sch during subcircuit creation.