Add .gitignore for KiCad, macOS, Linux, and Windows

Generated from gitignore.io with KiCad-specific additions from
github/gitignore. Keeps .net files (used as revision snapshots)
and .csv files (BOM exports) tracked.

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

.gitignore

@@ -0,0 +1,116 @@
+# Created by https://www.toptal.com/developers/gitignore/api/macos,linux,windows,kicad
+# Edit at https://www.toptal.com/developers/gitignore?templates=macos,linux,windows,kicad
+
+### KiCad ###
+# For PCBs designed using KiCad: https://www.kicad.org/
+# Format documentation: https://kicad.org/help/file-formats/
+
+# Temporary files
+*.000
+*.bak
+*.bck
+*.kicad_pcb-bak
+*.kicad_sch-bak
+*-backups/
+*-cache*
+*-bak
+*-bak*
+*.kicad_prl
+*.sch-bak
+*~
+~*
+_autosave-*
+\#auto_saved_files\#
+*.tmp
+*-save.pro
+*-save.kicad_pcb
+fp-info-cache
+~*.lck
+
+# Autorouter files (exported from Pcbnew)
+*.dsn
+*.ses
+
+# Exported BOM files
+*.xml
+
+### KiCad Patch ###
+rescue-backup/
+bom/
+
+# Gerber export output
+out/
+
+### Linux ###
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### macOS ###
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### macOS Patch ###
+# iCloud generated files
+*.icloud
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# End of https://www.toptal.com/developers/gitignore/api/macos,linux,windows,kicad