Initial project structure

Set up directories for KiCad hardware, firmware, and documentation.
Added .gitignore for KiCad and build artifacts.

.gitignore

@@ -0,0 +1,33 @@
+# KiCad
+*.bak
+*-backups/
+*-cache.lib
+*-cache.dcm
+*.kicad_prl
+*.kicad_pcb-bak
+*~
+\#*#
+_autosave-*
+*.tmp
+fp-info-cache
+
+# Gerber output
+gerbers/
+manufacturing/
+
+# Build artifacts
+firmware/build/
+firmware/.pio/
+*.o
+*.elf
+*.hex
+*.bin
+*.map
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store
+Thumbs.db