fix(security): bump Go to 1.24.13 to resolve stdlib vulnerabilities

Fixes GO-2026-4341 (net/url), GO-2025-3956 (os/exec),
GO-2025-3849 (database/sql), GO-2025-3750 (syscall).

Author: edouard-claude

go.mod

@@ -1,6 +1,6 @@
 module github.com/edouard-claude/snip
 
-go 1.24.3
+go 1.24.13
 
 require (
 	github.com/charmbracelet/lipgloss v1.1.0