fix(wind): decode in bounded virtual storage and test real canvas retention

src/data/windDecode.test.mjs

@@ -0,0 +1,9 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { decodeWindGribMessage } from '../../server/providers/wind/decode.js';
+test('decoder uses bounded virtual storage and releases both handle and message on errors', async () => {
+  const writes = []; let deleted = false;
+  const eccodesModule = { writeFile: (file, bytes) => writes.push(bytes.length), openGrib: () => ({ getLong: () => 1e9, delete: () => { deleted = true; } }) };
+  await assert.rejects(decodeWindGribMessage(new Uint8Array(20), { eccodesModule }), /geometry/);
+  assert.deepEqual(writes, [20,0]); assert.equal(deleted, true);
+});