Update electrical component links to use nightly-electrical release assets

Replaces broken preview branch links with direct release download URLs.
Drops unavailable pcb3d file, adds PCB Top/Bottom PDFs, BOM and
Interactive BOM which are now available as release assets.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: SukuWc

README.md

@@ -10,7 +10,7 @@ You can find more info on the [website](https://intech.studio/shop/knot) or in t
 
 | Component                 | Part number          | Preview | Links        |
 |---------------------------|----------------------|---------|--------------|
-| KNOT board            | PCBA-KNOT       | <img src="../preview/Preview/Electrical/PCBA-KNOT-3D_top.png?raw=true" width="150"> <img src="../preview/Preview/Electrical/PCBA-KNOT-3D_bottom.png?raw=true" width="150"> | [[Schematic]](../preview/Preview/Electrical/PCBA-KNOT_Schematic.pdf) [[STEP]](../preview/Preview/Electrical/PCBA-KNOT-3D.step?raw=true) [[Gerber]](../preview/Preview/Electrical/mfg/PCBA-KNOT-gerber.zip?raw=true)  [[PCB3D]](../preview/Preview/Electrical/PCBA-KNOT-blender_export.pcb3d?raw=true)  |
+| KNOT board            | PCBA-KNOT       | <img src="https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-3D_top.png" width="150"> <img src="https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-3D_bottom.png" width="150"> | [[Schematic]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT_Schematic.pdf) [[STEP]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-3D.step) [[Gerber]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-gerber.zip) [[PCB Top]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT_PCB_Top.pdf) [[PCB Bottom]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT_PCB_Bottom.pdf) [[BOM]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-bom.csv) [[Interactive BOM]](https://github.com/intechstudio/knot/releases/download/nightly-electrical/PCBA-KNOT-ibom.html) |
 
 ## Mechanical components