fix: auto-prune missing profile bundles and allow custom Windows installation paths

[yaojin3616]

Summary

• Auto-prune missing profile bundles before boot: automatically inspect profiles/web/package.json before running Harness. If any third-party bundle listed in dsh.profile.bundles or dependencies is missing from node_modules (e.g. manually deleted or uninstalled), Desktop automatically cleans up the stale bundle declarations and pnpm-lock.yaml. This prevents Harness from crashing with cannot resolve profile bundle.
• Atomic lockfile synchronization: ensure pnpm-lock.yaml is cleaned upon plugin reset/uninstall so pnpm does not crash with lockfileToHoistedDepGraph during subsequent plugin installs.
• Custom directory auto-creation in Windows NSIS installer: allow users to type arbitrary directory paths (e.g. D:\dsh-desktop) without requiring pre-existing folders by using an NSIS LEAVE hook to create the directory tree and overriding .onVerifyInstDir.
• Explicit Harness restart button: provide an instant restart action on the recovery page.

Verification

• npm run typecheck passed
• npm test passed (27 test suites, 172 tests)
• npm run build passed