fix(local-models): use pm pins and resumable component downloads

Use PM for engine binaries, dependent runtime archives, and model files.
Keep one operation-owned pause event through installation and download.
Report whole-plan bytes and retain paused jobs across desktop remounts.

Preserve the completed lm-pm worktree as its own integration parent.
The owning session verified focused Python and desktop tests, actual
Windows ARM64 CUDA downloads, and rendered pause/resume controls.
Combined verification with the safety repairs follows in the merge.

pm/packages.py

@@ -1102,6 +1102,16 @@ class LlamaCppVulkan(LlamaCpp):
     }
 
 
+@register
+class LlamaCppHip(LlamaCpp):
+    name = "llamacpp-hip"
+    backend = "hip"
+    assets = {
+        "win32-x64": "win-rocm-7.14-x64",
+        "linux-x64": "ubuntu-rocm-7.14-x64",
+    }
+
+
 @register
 class LlamaCppMetal(LlamaCpp):
     """macOS archives are unified builds with Metal compiled in."""