merge develop into validator-keys PR

Remove obsolete workflow patchelf handling, fold the validator-keys guide into the README, and write validator key files with owner-only permissions.

.github/scripts/levelization/results/ordering.txt

@@ -83,7 +83,6 @@ test.conditions > xrpl.basics
 test.conditions > xrpl.conditions
 test.consensus > test.csf
 test.consensus > test.jtx
-test.consensus > test.toplevel
 test.consensus > test.unit_test
 test.consensus > xrpl.basics
 test.consensus > xrpld.app

.github/scripts/strategy-matrix/linux.json

@@ -1,5 +1,5 @@
 {
-  "image_tag": "sha-fe4c8ae",
+  "image_tag": "sha-e29b523",
   "configs": {
     "ubuntu": [
       {

.github/scripts/strategy-matrix/windows.json

@@ -1,6 +1,6 @@
 {
   "platform": "windows/amd64",
-  "runner": ["self-hosted", "Windows", "devbox"],
+  "runner": ["self-hosted", "Windows", "dev-box-windows-2026"],
   "configs": [
     { "build_type": "Release" },
     {