n watch: support worktree-overridden plugins inside isolated envs

[dkoo]

Summary

n watch <name> (per-project watch) does not work for a worktree-overridden plugin inside an isolated env. This is a known limitation, surfaced during review of #205 (the stacked fix for #188's global watch).

Background

In an isolated env (bin/env.sh), a --worktree <repo>:<branch> override is mounted at /newspack-plugins/<name> (overlaying the base ./plugins mount), while /newspack-monorepo is the base workspace checkout.

• Before chore(n): harden global watch dispatcher and fix env path remap #205, bin/watch-repo.sh unconditionally remapped /newspack-plugins/<name> → /newspack-monorepo/plugins/<name>, so n watch <name> in an env silently watched the base (main) branch instead of the worktree under test.
• chore(n): harden global watch dispatcher and fix env path remap #205 added an -ef (same-inode) guard so the remap only fires when both paths are the same directory. This correctly stops the silent wrong-branch build — but it leaves watch pointed at /newspack-plugins/<name>, whose pnpm workspace symlinks (node_modules/newspack-scripts -> ../../../packages/scripts) escape the single-subdir mount, so wp-scripts doesn't resolve and the watch toolchain hard-fails.

Net: #205 converts a silent wrong-branch build into a correct build / honest failure — an improvement — but watching a worktree-overridden plugin in an env still doesn't actually run.

Proposed approach (from review)

When the base /newspack-monorepo/{plugins,themes,repos}/<name> remap fails the -ef check (i.e. we're looking at a worktree override), resolve the override's branch-under-test under the monorepo mount instead:

• /newspack-monorepo/worktrees/<safe_branch>/{plugins,themes}/<name> is the same host directory as the /newspack-plugins/<name> override (verifiable via -ef) and lives under /newspack-monorepo, so the worktree's relative pnpm symlinks resolve.
• cd there and run npm run watch.

Open question / dependency

This only fully works if the worktree has its deps installed — bin/worktree.sh add does not run pnpm install, so a fresh worktree's node_modules/.bin/wp-scripts won't exist even at the resolvable path. The fix likely needs to either ensure deps are installed in the worktree or detect-and-message when they aren't.

References

• chore(n): add global n watch for all plugins/themes/packages #188 — global n watch (base feature)
• chore(n): harden global watch dispatcher and fix env path remap #205 — -ef guard that scopes the remap (this issue is the documented follow-up)