feat(web): implement Ship List page with create and delete modals

Adds ship cards with navigation, create ship modal with initial stats,
inline delete confirmation, and supporting CSS for modals and cards.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/ui/Modal.tsx

@@ -0,0 +1,35 @@
+import { useEffect, type ReactNode } from 'react';
+
+interface ModalProps {
+  open: boolean;
+  onClose: () => void;
+  title: string;
+  children: ReactNode;
+}
+
+export default function Modal({ open, onClose, title, children }: ModalProps) {
+  useEffect(() => {
+    if (!open) return;
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [open, onClose]);
+
+  if (!open) return null;
+
+  return (
+    <div className="modal-overlay" onClick={onClose}>
+      <div className="modal-content" onClick={(e) => e.stopPropagation()}>
+        <div className="modal-header">
+          <h2 className="modal-title">{title}</h2>
+          <button className="btn-icon" onClick={onClose}>
+            &times;
+          </button>
+        </div>
+        {children}
+      </div>
+    </div>
+  );
+}