chore: add .gitignore (exclude binaries, logs, local config)

.gitignore

@@ -0,0 +1,39 @@
+# Binaries and build outputs
+/bin/
+/*.exe
+*.exe
+*.out
+*.test
+
+# Project-specific binary
+safelineApi.exe
+
+# Go build caches and tools
+# (keep go.mod and go.sum committed)
+Godeps/
+
+# Dependency directories
+vendor/
+
+# Configuration (local secrets)
+config.json
+.env
+.env.local
+
+# Editor directories and files
+.vscode/
+.idea/
+*.iml
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Logs and temp
+*.log
+tmp/
+temp/
+
+# Misc
+*.swp
+*.swo