📝 Add docstrings to feat/go-rewrite

Docstrings generation was requested by @blakeridgway.

* https://github.com/RideAware/admin-panel/pull/1#issuecomment-3528008426

The following files were modified:

* `cmd/admin-panel/main.go`
* `internal/config/config.go`
* `internal/database/database.go`
* `internal/email/email.go`
* `internal/handlers/auth.go`
* `internal/handlers/newsletter.go`
* `internal/handlers/subscribers.go`
* `internal/middleware/auth.go`

internal/middleware/auth.go

@@ -11,6 +11,9 @@ import (
 
 var store *sessions.CookieStore
 
+// Init initializes the package-level cookie store used for session management.
+// It panics if config.Current.SecretKey is empty.
+// The created store is configured with Path "/", MaxAge one week, HttpOnly true, Secure false, and SameSite 0.
 func Init() {
 	if config.Current.SecretKey == "" {
 		panic("SECRET_KEY not set")
@@ -25,10 +28,16 @@ func Init() {
 	}
 }
 
+// GetStore returns the package-level Gorilla cookie store used for session management.
+// It may be nil if Init has not been called.
 func GetStore() *sessions.CookieStore {
 	return store
 }
 
+// Auth enforces session-based authentication for Gin handlers.
+// If the request has no session named "session" or the session lacks a "username" value,
+// the middleware redirects to "/login" (HTTP 302) and aborts further handling.
+// Otherwise the middleware calls the next handler in the chain.
 func Auth() gin.HandlerFunc {
 	return func(c *gin.Context) {
 		session, err := store.Get(c.Request, "session")