fix: split redox.patch into 90MB chunks for GitHub push limit

redox.patch is 556MB, exceeding GitHub's 100MB file size limit.
Split into 7 chunks of ~90MB each under local/patches/base/redox-patch-chunks/.
Reassembly script: local/patches/base/reassemble-redox-patch.sh.
Added redox.patch to .gitignore to prevent future push failures.

local/patches/base/reassemble-redox-patch.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Reassemble redox.patch from split chunks (needed because the full patch
+# exceeds GitHub's 100 MB file size limit).
+#
+# Usage:
+#   cd local/patches/base/
+#   bash reassemble-redox-patch.sh
+
+set -euo pipefail
+cd "$(dirname "$0")"
+cat redox-patch-chunks/chunk_* > redox.patch
+echo "Reassembled redox.patch ($(wc -c < redox.patch) bytes)"