feat: initialize Go project with basic setup

Add initial project files:
- .air.toml for live reload configuration
- .gitignore for temporary and environment files
- go.mod with module and Go version
- main.go with a simple Hello World program

This sets up the foundation for further development.

.air.toml

@@ -0,0 +1,52 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "./tmp/main"
+  cmd = "go build -o ./tmp/main ."
+  delay = 1000
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = ["_test.go"]
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  post_cmd = []
+  pre_cmd = []
+  rerun = false
+  rerun_delay = 500
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  silent = false
+  time = false
+
+[misc]
+  clean_on_exit = false
+
+[proxy]
+  app_port = 0
+  enabled = false
+  proxy_port = 0
+
+[screen]
+  clear_on_rebuild = false
+  keep_scroll = true

.gitignore

@@ -0,0 +1,2 @@
+tmp/
+.env*

go.mod

@@ -0,0 +1,3 @@
+module github.com/rjnemo/auth
+
+go 1.24.5

main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello, World!")
+}