bug(cli): nodeup list is an unimplemented stub, contradicts README and breaks --json scripting

[dipto0321]

Describe the bug

Two related problems in the package-restore path:

1. installPackages aborts on the first failed install. internal/packages/snapshot.go:171-179:

   for _, pkg := range pkgs {
       ...
       if err != nil {
           return err
       }
   }

   A single failed npm install -g (404, deprecated/unpublished package, transient network error) stops the loop entirely — every later package in the snapshot is silently never attempted.

2. MigrationReport is fully dead code. internal/packages/report.go's NewMigrationReport, AddResult, and Save() have zero call sites anywhere in the repo (confirmed by repo-wide grep). Despite README/CHANGELOG describing a "migration report" as a Phase 3 deliverable, no report is ever written to <DataDir>/reports/. Failures surface only as a single cmd.Printf("Warning: restore failed: %v\n") with no per-package detail (which package failed, how many were skipped).

Suggested fix

• Change installPackages to continue past a failed install, collecting a PackageResult per package (success/failed/skipped) instead of returning on the first error.
• Either wire MigrationReport into this loop and write it to <DataDir>/reports/ on every restore (matching the documented feature), or remove report.go entirely if the report feature is being deprioritized — don't leave a half-built, unused type in place.

Severity

High — failed migrations are invisible to the user beyond one generic warning line, and the rest of the snapshot silently never gets restored.