fix(installer): symlink bundled node/npm into command bin dir for FHS root installs

[alt-glitch]

Summary

Root installs on Linux (FHS layout, #15608) put the hermes command in
/usr/local/bin (on PATH) but symlinked the bundled node/npm/npx into
~/.local/bin, which isn't on PATH for a stock root shell. Result:
node/npm are "command not found" and hermes dashboard fails with
"npm is not available".

Root Cause

install_node() (scripts/install.sh:845) hardcodes $HOME/.local/bin for the
node symlinks. But get_command_link_dir() — the helper the hermes command
already uses — correctly returns /usr/local/bin for root FHS installs.
PR #15608 created the FHS path for the command but left install_node pointed
at the legacy user-local dir.

The PATH-guard (install.sh:1538+) doesn't self-heal this because it checks
$command_link_dir (= /usr/local/bin, already on PATH), so it's a no-op for
the exact case that needs it.

Fix

• scripts/install.sh: install_node() now symlinks into
  get_command_link_dir() — same helper the hermes command link uses.
  /usr/local/bin on FHS root, ~/.local/bin otherwise, $PREFIX/bin on Termux.
• scripts/lib/node-bootstrap.sh: new _nb_get_link_dir() mirrors the
  same logic for the standalone bootstrap path (used by hermes update, TUI
  node bootstrap).
• hermes_cli/uninstall.py: remove_node_symlinks() now checks all
  candidate directories so root FHS uninstalls don't leave orphan symlinks in
  /usr/local/bin.

Non-root and Termux installs are unchanged (same symlink target as before).

Reproduction & Verification

Tested on a clean Ubuntu 24.04 VM (libvirt, cloud image):

Step	Before (bug)	After (fix)
Fresh root install (curl | bash)	node → /root/.local/bin/ (not on PATH)	node → /usr/local/bin/ (on PATH ✓)
command -v node in stock root shell	NOT FOUND	/usr/local/bin/node ✓
hermes dashboard	"npm is not available"	builds web UI, serves HTTP 200 ✓

Test Plan

• Existing 6 uninstall tests pass
• New test_removes_fhs_symlinks_in_usr_local_bin covers FHS path
• Clean VM end-to-end: root install → node resolves → hermes dashboard builds + serves

Infographic

[github-actions]

🔎 Lint report: fix/node-symlink-fhs-root-install vs origin/main

ruff

Total: 0 on HEAD, 0 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 0 pre-existing issues carried over.

ty (type checker)

Total: 9788 on HEAD, 9788 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 5081 pre-existing issues carried over.

Diagnostics are surfaced as warnings — this check never fails the build.

[alt-glitch]

Review response — hardening + scope decisions

Thanks for the sharp review. Addressed the high/medium items in commit 2ff73853e, verified the two you said to hammer (#1 migration, dashboard build) on a throwaway VM, and made explicit scope calls on the rest.

Fixed

#1 Existing-broken-install → update/migration (the trap). Confirmed and fixed. ensure_node() (node-bootstrap.sh) and check_node() (install.sh) both early-returned when a bundled node already existed, only fixing the current shell's PATH and never re-creating the /usr/local/bin symlinks — so a previously-broken root box stayed broken after hermes update. Both now call a shared link_bundled_node / _nb_link_bundled_node that idempotently re-links into the canonical dir.

#2 Stale ~/.local/bin orphans. The re-link helpers now prune stale node/npm/npx links in the other candidate dirs (target-checked: only links resolving into this hermes home's node dir are removed — never a real binary or an nvm/fnm link). So a migrated root box no longer keeps shadowing copies in ~/.local/bin.

#4 Parity. _nb_get_link_dir() now mirrors resolve_install_layout()'s legacy-install carve-out (root user with $HERMES_HOME/hermes-agent/.git keeps ~/.local/bin), so the bootstrap path can't link node to a different dir than the installer put the command. Also consolidated the duplicated layout logic into one canonical helper in hermes_constants (command_link_dir / command_link_candidate_dirs / bundled_node_bin_dir / find_node_executable), now consumed by doctor, profiles, uninstall, backup, main.

Doctor now catches this regression class (it previously couldn't): hermes doctor reports "Node.js installed but not on PATH" instead of a false "not found", verifies the /usr/local/bin/node symlink on root FHS, and the npm-audit block no longer silently vanishes when npm is off-PATH. Also fixed doctor's own command-link detection (was hardcoded ~/.local/bin, would create a wrong duplicate symlink with --fix on root FHS).

Bonus FHS bugs found in the audit + fixed: profile-alias wrappers (hermes profile) were hardcoded to ~/.local/bin → off-PATH for root FHS; now layout-aware, and removal scans all candidate dirs. Defensive bundled-node fallback added to the dashboard web-UI build, WhatsApp bridge, and LSP installer.

Verified (throwaway Ubuntu 24.04 VM, libvirt)

A scenario matrix (fresh-root / migration / fresh-nonroot / uninstall), run against the patched install.sh:

• fresh-root ✓ node resolves in a stock non-login root shell, symlink in /usr/local/bin, none left in ~/.local/bin, hermes dashboard serves HTTP 200, web_dist built, tsc present.
• migration ✓ install → simulate old broken layout (links only in ~/.local/bin, off root PATH; precondition asserts node is genuinely unreachable) → re-run installer → node restored to /usr/local/bin, stale ~/.local/bin/node pruned.

#7 dashboard tsc: not found

Does not reproduce on a fresh root install — node_modules/.bin/tsc is properly hoisted with the bundled node v22 and the build completes to HTTP 200. The original report was a corrupted/partial node_modules from an interrupted install, not a layout defect. The web-UI build now also injects the bundled node bin dir into the build subprocess PATH so tsc/vite (which re-invoke node) work even from a stripped-PATH context.

Deliberately scoped OUT (separate issues, will file follow-ups)

• Architecture planning #3 npm global-prefix hijack ([Bug]: Setup SABOTAGES computer integrits - npm global installs hijacked to ~/.hermes/node breaks other software #18357/fix(install): prevent npm symlink from hijacking user global npm prefix #18379). This PR moves where the symlinks point; it does not touch npm config set prefix. That's a distinct concern with its own design tradeoffs — folding it in here would muddy a focused PATH fix. Tracking separately rather than silently leaving it.
• Add logging for first 100 chars of the tool call args json / tool response #9 install.ps1 (Windows). No /usr/local/bin FHS notion on Windows, so the root-FHS bug class doesn't apply; the shared _get_wrapper_dir change preserves the Windows ~/.local/bin-equivalent branch. Follow-up issue for a Windows audit.

Unit tests: +9 hermes_constants helper tests, +4 profiles wrapper-dir tests; existing doctor/profiles/backup/uninstall/constants suites all green.