Add Gerber manufacturing files and export script

Generated files:
- gerbers/: All Gerber layers, drill files, pick-and-place CSV
- SN-L00-gerbers.zip: Ready for upload to PCB fab
- scripts/export_gerbers.sh: Regenerate with one command

Layers: F.Cu, B.Cu, F/B.Paste, F/B.Silkscreen, F/B.Mask, Edge.Cuts

hardware/kicad/scripts/export_gerbers.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+# Export Gerbers, drill files, and pick-and-place for PCB manufacturing
+# Usage: ./scripts/export_gerbers.sh
+
+set -e
+cd "$(dirname "$0")/.."
+
+PCB_FILE="SN-L00.kicad_pcb"
+OUT_DIR="gerbers"
+ZIP_FILE="SN-L00-gerbers.zip"
+
+echo "============================================"
+echo "SN-L00 Gerber Export"
+echo "============================================"
+
+# Clean and create output directory
+rm -rf "$OUT_DIR" "$ZIP_FILE"
+mkdir -p "$OUT_DIR"
+
+# Export Gerbers
+echo "[1/4] Exporting Gerber layers..."
+kicad-cli pcb export gerbers \
+  -o "$OUT_DIR/" \
+  -l "F.Cu,B.Cu,F.Paste,B.Paste,F.Silkscreen,B.Silkscreen,F.Mask,B.Mask,Edge.Cuts" \
+  "$PCB_FILE"
+
+# Export drill files
+echo "[2/4] Exporting drill files..."
+kicad-cli pcb export drill \
+  -o "$OUT_DIR/" \
+  --format excellon \
+  --drill-origin absolute \
+  --excellon-zeros-format decimal \
+  --excellon-units mm \
+  --generate-map \
+  --map-format gerberx2 \
+  "$PCB_FILE"
+
+# Export pick and place
+echo "[3/4] Exporting pick and place..."
+kicad-cli pcb export pos \
+  -o "$OUT_DIR/SN-L00-pos.csv" \
+  --format csv \
+  --units mm \
+  --side both \
+  --use-drill-file-origin \
+  "$PCB_FILE"
+
+# Create zip
+echo "[4/4] Creating zip archive..."
+cd "$OUT_DIR"
+zip -r "../$ZIP_FILE" .
+cd ..
+
+echo ""
+echo "============================================"
+echo "Generated files:"
+ls -lh "$OUT_DIR"/
+echo ""
+echo "Upload to fab: $ZIP_FILE ($(du -h "$ZIP_FILE" | cut -f1))"
+echo "============================================"