Decompiled-source temp files are shared across sidecar processes and written without sharing — Windows write race

From the multi-agent audit (sidecars/SharpLsp.Sidecar.CSharp/Workspace/MetadataNavigator.cs ~173): decompiled [metadata] sources are materialized under a temp path shared by ALL sidecar processes and written with exclusive access. Two editor windows decompiling the same type race: the second write throws IOException (file in use) or one process reads a half-written file. Key the path by process (or write-to-temp + atomic rename, tolerating Exists).

Start in sidecars/SharpLsp.Sidecar.CSharp/Workspace/MetadataNavigator.cs around line 173 and trace how decompiled [metadata] sources are materialized and opened. Reproduce two sidecar processes decompiling the same type, then verify that concurrent writes no longer raise IOException and readers cannot observe a half-written file.