codec: update vendored VaptVupt codec 2.65.0 -> 2.65.3

From vaptvupt-codec tag v2.65.3. Output is byte-identical to 2.65.0 (same
ratio, wire format v1.6 unchanged) but extreme-mode encode is ~1.6-2x faster
(Sprint 132 optimal-parser speedup) and the extreme prepass window allocation
is capped at wlog=20 = 8 MiB virtual instead of up to 128 MiB (Sprint 133
memory hygiene). Our AVX2 offset-read decoder guard is now UPSTREAM (dropped
from the local patch set); the ANS safe-zone 2*SAFEZONE_MAX_RUN reserve is
re-applied on top (still not upstream). make check 16/16, KAT 16/16, cross-
version roundtrip with 5.1.0 archives verified.

vendor/vuptsdk/include/vaptvupt_api.h

@@ -0,0 +1,43 @@
+/*
+ * VaptVupt — Zupt Integration API
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright 2026 Cristian.
+ *
+ * ZUPT-COMPAT: This is the API that Zupt calls. It wraps the internal
+ * VaptVupt API with sensible defaults for backup workloads:
+ *   - Checksum always enabled (data integrity is critical for backups)
+ *   - Adaptive window selection (auto-detect optimal wlog per file)
+ *   - Level maps to mode: 1=fast, 5=balanced, 9=extreme
+ *
+ * Usage:
+ *   size_t bound = vvz_compress_bound(src_len);
+ *   uint8_t *dst = malloc(bound);
+ *   int64_t csz = vvz_compress(src, src_len, dst, bound, 5);
+ *   int64_t dsz = vvz_decompress(dst, csz, out, out_cap);
+ */
+#ifndef VAPTVUPT_API_H
+#define VAPTVUPT_API_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Compress src into dst. Returns compressed size or negative error code.
+ * level: 1 = fast (max speed), 5 = balanced (default), 9 = extreme (max ratio) */
+int64_t vvz_compress(const uint8_t *src, size_t src_len,
+                     uint8_t *dst, size_t dst_cap, int level);
+
+/* Decompress src into dst. Returns decompressed size or negative error code. */
+int64_t vvz_decompress(const uint8_t *src, size_t src_len,
+                       uint8_t *dst, size_t dst_cap);
+
+/* Upper bound on compressed size for a given input length. */
+size_t vvz_compress_bound(size_t src_len);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* VAPTVUPT_API_H */