fix(cli): rename running binary before copy in Windows dogfood tasks

Windows locks running executables preventing overwrite. The fix renames
the running binary to .old first (which Windows allows), then copies
the new binary to the original path.

Author: CalvinAllen

rnr.yaml

@@ -33,11 +33,11 @@ build:
 # Use the task matching your platform, or dogfood-all for all platforms
 dogfood-windows-amd64:
   description: Build and install to .rnr/bin (Windows x64)
-  cmd: cargo build --release && copy /Y target\release\rnr.exe .rnr\bin\rnr-windows-amd64.exe
+  cmd: cargo build --release && ren .rnr\bin\rnr-windows-amd64.exe rnr-windows-amd64.exe.old 2>nul & copy /Y target\release\rnr.exe .rnr\bin\rnr-windows-amd64.exe
 
 dogfood-windows-arm64:
   description: Build and install to .rnr/bin (Windows ARM64)
-  cmd: cargo build --release && copy /Y target\release\rnr.exe .rnr\bin\rnr-windows-arm64.exe
+  cmd: cargo build --release && ren .rnr\bin\rnr-windows-arm64.exe rnr-windows-arm64.exe.old 2>nul & copy /Y target\release\rnr.exe .rnr\bin\rnr-windows-arm64.exe
 
 dogfood-linux-amd64:
   description: Build and install to .rnr/bin (Linux x64)