fix: show full parent command path in subcommand usage errors

[shaanmajid]

Summary

• Subcommand runtime usage errors (e.g., npm stage approve without a <stage-id>) rendered the bare subcommand name (e.g., npm approve <stage-id>) and Run "npm help approve" for more info -- pointing at a command and help page that don't exist.
• The subcommand instance now carries its parent command name, so usage output and usageError render the full path (npm stage approve <stage-id>) and point to the real help page (npm help stage)

This fix applies to npm stage and npm trust.

Implementation

• lib/npm.js: set parentName on the subcommand instance during dispatch (and use the full joined path on the --help branch for parity).
• lib/base-cmd.js: the instance usage getter threads parentName into getUsage, and the help footer resolves to the top-level documented command.

References

Fixes #9403

[swarnim-dev]

Tested this locally and can confirm it works. Ran the test suite and everything passes:

• stage/approve tests: 5/5 ✅
• trust command tests: 71 assertions across 5 files ✅

The fix does what it's supposed to - error messages now show the full command path like "npm stage approve " instead of the broken "npm approve ". Verified it works for both stage and trust subcommands.

Code looks solid, no edge cases I can find, and there's good test coverage.

Ready to ship acc. to me!

[shaanmajid]

CI failures were from stale snapshot; should be fixed with 40655c0

[github-actions]

⚠️ Backport to release/v11 failed.

This usually means the cherry-pick had conflicts. Please create a manual backport:

git fetch origin release/v11
git checkout -b backport/v11/9404 origin/release/v11
git cherry-pick -x fe41ae7c6b38e7e9957b646bf379e2b5daae03f9
# resolve any conflicts, then:
git push origin backport/v11/9404

Error details

Command failed: git cherry-pick -x fe41ae7c6b38e7e9957b646bf379e2b5daae03f9
error: could not apply fe41ae7c6... fix: show full parent command path in subcommand usage errors (#9404)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"