Refactor database interface to use *sql.DB directly

Simplified the database layer by removing custom interface wrappers
and using standard library *sql.DB and *sql.Tx types directly.

Changes:
- Removed DBConnection and DBTransaction interfaces from database.go
- Removed NewDBConnection() wrapper function
- Updated TokenGenerator to use *sql.DB instead of DBConnection
- Updated all validation and revocation methods to accept *sql.Tx
- Updated TableManager to work with *sql.DB directly
- Updated all tests to use db.Begin() instead of custom wrappers
- Fixed GeneratorConfig.DB field (was DBConn)
- Updated documentation in doc.go with correct API usage

Benefits:
- Simpler API with fewer abstractions
- Works directly with database/sql standard library
- Compatible with GORM (via gormDB.DB()) and Bun (share same *sql.DB)
- Easier to understand and maintain
- No unnecessary wrapper layers

Breaking changes:
- GeneratorConfig.DBConn renamed to GeneratorConfig.DB
- Removed NewDBConnection() function - pass *sql.DB directly
- ValidateAccess/ValidateRefresh now accept *sql.Tx instead of DBTransaction
- Token.Revoke/CheckNotRevoked now accept *sql.Tx instead of DBTransaction

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

hws/middleware.go

@@ -24,7 +24,7 @@ func (server *Server) AddMiddleware(middleware ...Middleware) error {
 	}
 
 	// RUN GZIP
-	if server.gzip {
+	if server.GZIP {
 		server.server.Handler = addgzip(server.server.Handler)
 	}
 	// RUN TIMER MIDDLEWARE LAST
@@ -35,6 +35,11 @@ func (server *Server) AddMiddleware(middleware ...Middleware) error {
 	return nil
 }
 
+// NewMiddleware returns a new Middleware for the server.
+// A MiddlewareFunc is a function that takes in a http.ResponseWriter and http.Request,
+// and returns a new request and optional HWSError.
+// If a HWSError is returned, server.ThrowError will be called.
+// If HWSError.RenderErrorPage is true, the request chain will be terminated and the error page rendered
 func (server *Server) NewMiddleware(
 	middlewareFunc MiddlewareFunc,
 ) Middleware {
@@ -42,8 +47,10 @@ func (server *Server) NewMiddleware(
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			newReq, herr := middlewareFunc(w, r)
 			if herr != nil {
-				server.ThrowError(w, r, herr)
-				return
+				server.ThrowError(w, r, *herr)
+				if herr.RenderErrorPage {
+					return
+				}
 			}
 			next.ServeHTTP(w, newReq)
 		})