Guard Linux speech runtime dependency closure and relocatable lookup

tools/speech-runtime/README.md

@@ -20,6 +20,11 @@ inventory files before launch and incorporates the inventory hash in its source
 completion fingerprint. A changed backend DLL therefore invalidates reuse.
 The builder compiles only; native Linux/macOS loading, full system-dependency
 closure, actual GPU speed/fallback and release packaging still require evidence.
+Normal Linux builds reject staged ELF files with build-tree RUNPATH or undeclared
+dependencies. Each shared target uses `$ORIGIN` for relocation; a system Vulkan
+loader is permitted only for the dynamically loaded Vulkan backend. The declared
+system C/C++ libraries remain a distribution compatibility requirement. A full
+relocated recognition test is still required after compilation.
 Windows auto builds reuse the verified Vulkan SDK/loader provisioning and selected
 Visual Studio CRT bundling helpers. The isolated runtime inventories its own
 `vulkan-1.dll`, full release CRT set and their redistribution notices. Shared helper