fix(workspaces): preserve detached work and journaled Git sources

Reject retained worktree paths and orphan indexes before branch-only import. Revalidate the source path from interrupted migration journals. Use the cleanup producer command formatter for clean user-owned removal receipts.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/services/workspace-command-display.ts

@@ -0,0 +1,5 @@
+export function formatCommandForDisplay(command: string, args: string[]) {
+  return [command, ...args]
+    .map((part) => (/^[A-Za-z0-9_./:-]+$/.test(part) ? part : JSON.stringify(part)))
+    .join(" ");
+}