Add comprehensive .gitignore for clean repository

.gitignore

@@ -0,0 +1,141 @@
+# Arduino/ESP32 Build Files
+*.o
+*.elf
+*.bin
+*.hex
+*.map
+*.lst
+*.d
+*.eep
+*.lss
+*.sym
+
+# Arduino IDE
+.build/
+build/
+*.ino.cpp
+*.ino.hex
+*.ino.elf
+*.ino.map
+*.ino.with_bootloader.bin
+*.ino.bootloader.bin
+*.ino.partitions.bin
+
+# PlatformIO
+.pio/
+.pioenvs/
+.piolibdeps/
+.vscode/
+.clang_complete
+.gcc-flags.json
+lib/readme.txt
+
+# VS Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+*.code-workspace
+
+# JetBrains IDEs
+.idea/
+*.iml
+*.iws
+*.ipr
+cmake-build-*/
+
+# macOS
+.DS_Store
+.AppleDouble
+.LSOverride
+._*
+
+# Windows
+Thumbs.db
+ehthumbs.db
+Desktop.ini
+$RECYCLE.BIN/
+*.lnk
+
+# Linux
+*~
+.directory
+.Trash-*
+
+# Backup files
+*.bak
+*.backup
+*.old
+*.orig
+*.tmp
+*~
+
+# Log files
+*.log
+debug.log
+error.log
+
+# Compiled Python files
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+
+# Virtual environments
+venv/
+env/
+ENV/
+.venv/
+
+# Test files
+test/
+tests/
+testing/
+*.test
+
+# Documentation build
+docs/_build/
+docs/.doctrees/
+
+# Package files
+*.zip
+*.tar
+*.tar.gz
+*.rar
+*.7z
+
+# Config files with secrets
+config.h
+secrets.h
+passwords.h
+credentials.h
+*.secret
+
+# Editor-specific
+*.swp
+*.swo
+*~
+.*.sw?
+
+# Build artifacts
+firmware.bin
+bootloader.bin
+partitions.bin
+
+# Certificates and keys
+*.pem
+*.key
+*.crt
+*.cer
+*.p12
+
+# Database files
+*.db
+*.sqlite
+*.sqlite3
+
+# Temporary hardware notes
+**/scratchpad.txt
+**/notes.txt
+**/todo.txt