fix(local-runtime): move a pre-PM llama.cpp engine into the PM store and pin b10964

The package-manager switch (#102765) made engine detection read only PM's
store and pinned every llama.cpp backend to b10362. A machine with an
engine under runtimes/llamacpp/b<tag>/<backend>/ reported no engine, so
the local models pane showed one-click setup with models already on disk.

installed_engine() now moves the newest pre-PM install into the store
once. The old manifest's archive digests become the PM identity, the
package verifier runs llama-server --version, and os.rename puts the
directory in place before facts.json records it. A store that already
holds an engine is left alone, a store lock held by another PM operation
defers the move, and an install that fails verification stays where it
is for the rest of the process.

The lock returns to b10964 on all five backends, the default before the
PM switch. With b10362 pinned, the pane offered a downgrade from the
moved engine as an update. Upstream renamed the ROCm archives to 10.0 at
b10767, and the hip assets follow. Only the CUDA build is measured at
b10964.

pm/packages.py

@@ -1098,9 +1098,10 @@ class LlamaCppVulkan(LlamaCpp):
 class LlamaCppHip(LlamaCpp):
     name = "llamacpp-hip"
     backend = "hip"
+    # Upstream renamed the ROCm archives to 10.0 at b10767 (cff184438e).
     assets = {
-        "win32-x64": "win-rocm-7.14-x64",
-        "linux-x64": "ubuntu-rocm-7.14-x64",
+        "win32-x64": "win-rocm-10.0-x64",
+        "linux-x64": "ubuntu-rocm-10.0-x64",
     }