feat: Complete project cleanup and Rev. 0.3 updates

- Remove unused schematic files (mcu.kicad_sch, PWR.kicad_sch)
- Update version numbering to semantic versioning (Rev. 0.0/0.1)
- Add comprehensive changelog documentation in both languages
- Create separate CHANGELOG.md and CHANGELOG.de.md files
- Update PCB to Rev. 0.3 with layout optimizations
- Professional 4-layer PCB design with optimal via stitching
- Excellent differential pair routing for CAN-bus (< 18mm)
- Superior thermal management with 19 vias at PFET drain
- Strategic power plane distribution and EMI considerations
- Production-ready PCB layout with best practices implementation

Laser CANbus Toolhead.kicad_pro

@@ -125,7 +125,7 @@
         "max_error": 0.005,
         "min_clearance": 0.0,
         "min_connection": 0.0,
-        "min_copper_edge_clearance": 0.5,
+        "min_copper_edge_clearance": 0.2,
         "min_groove_width": 0.0,
         "min_hole_clearance": 0.25,
         "min_hole_to_hole": 0.25,
@@ -713,5 +713,7 @@
       "Root"
     ]
   ],
-  "text_variables": {}
+  "text_variables": {
+    "PROJEKT_REV": "0.3"
+  }
 }