refactor: reorganize project structure and update configurations

- Move migrations/ to database/schema/ for clarity on database schema definitions
- Move sqlc.yaml to internal/database/ to group with database code
- Move static/ to cmd/server/static/ to co-locate with server
- Update all configuration files and documentation
- Follow Go project conventions for better organization

templates/login.templ

@@ -7,8 +7,8 @@ templ Login() {
         <meta charset="UTF-8">
         <meta name="viewport" content="width=device-width, initial-scale=1.0">
         <title>Login</title>
-        <script src="https://cdn.tailwindcss.com"></script>
-        <script src="https://unpkg.com/htmx.org@1.9.10"></script>
+        <script src="/static/htmx.min.js"></script>
+        <link href="/static/style.css" rel="stylesheet">
         <style>
             :root {
                 --bg-primary: #1a1b26;