fix(doctor): detect agent-browser in the Hermes-managed node bin (#53192)

[AgenticSpark]

What does this PR do?

hermes acp --setup-browser --yes installs agent-browser into the Hermes-managed
node prefix at ~/.hermes/node/bin/agent-browser, which isn't necessarily on PATH.
hermes doctor only checked PROJECT_ROOT/node_modules and PATH (shutil.which),
so it reported agent-browser not installed (run: npm install) even though the binary
was present and runnable — a discovery false negative, not an install failure (#53192).

This mirrors the detection hermes_cli/dep_ensure.py::_has_hermes_agent_browser()
already does, so doctor and dep_ensure agree on what "installed" means.

Related Issue

Fixes #53192

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• hermes_cli/doctor.py: in the Node.js + agent-browser check, look for the binary in
  HERMES_HOME/node/bin/agent-browser and the legacy HERMES_HOME/node_modules/.bin/agent-browser
  before warning, each gated by agent_browser_runnable() (the same dangling-symlink guard
  the existing PATH branch uses). PATH, node_modules, and Termux behavior are unchanged.
• tests/hermes_cli/test_doctor.py: added a positive case (managed bin present and runnable →
  detected, no warning) and a negative case (present but not runnable → still warns).

How to Test

1. With node installed and agent-browser only at ~/.hermes/node/bin/agent-browser (not on PATH,
   no node_modules/agent-browser), run hermes doctor — it now reports agent-browser OK instead of
   "not installed".
2. pytest tests/hermes_cli/test_doctor.py -q → all green (66 passed).

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix
• I've run pytest tests/hermes_cli/test_doctor.py -q and all tests pass
• I've added tests for my changes
• I've tested on my platform: Ubuntu 24.04

Documentation & Housekeeping

• I've updated relevant documentation — N/A (behavior-only fix)
• I've updated cli-config.yaml.example if I added/changed config keys — N/A
• I've updated CONTRIBUTING.md or AGENTS.md — N/A
• I've considered cross-platform impact — the new paths match the non-Windows branch of
  dep_ensure._has_hermes_agent_browser(); the existing Windows .cmd handling there is unchanged
• I've updated tool descriptions/schemas if I changed tool behavior — N/A

[teknium1]

Thanks for addressing a real current-main diagnostic gap: hermes_cli/doctor.py:1556-1580 still checks only the project install and PATH, while ACP setup routes through ensure_dependency("browser") (acp_adapter/entry.py:189-211) and the POSIX installer places the executable at $HERMES_HOME/node/bin/agent-browser (scripts/install.sh:2479-2503).

Problems

• The new candidates omit the Windows managed layout. scripts/install.ps1:363-371 installs under $HERMES_HOME/node, and scripts/install.ps1:389-395 invokes $HERMES_HOME/node/agent-browser.cmd. The proposed POSIX-only candidates would leave hermes doctor false-negative on that installation. hermes_cli/dep_ensure.py:60-70 already distinguishes this .cmd location.

Suggested changes

• Add and validate the Windows .cmd managed candidate, and cover it with a doctor regression test.

Automated hermes-sweeper review.

[teknium1]

This adds only the POSIX prefix layout. scripts/install.ps1:389-395 installs and invokes the managed Windows shim at HERMES_HOME/node/agent-browser.cmd; add that platform-specific candidate (also through agent_browser_runnable) or Windows hermes doctor will retain the same false negative.

[teknium1]

Landed on main via #73959 — your commit was cherry-picked with authorship preserved (f170113 → rebase-merged at c892ca2), plus a follow-up widening the managed/legacy dir probes to PATHEXT-aware shutil.which resolution so the Windows .cmd shim is found too (same class fix as #73932). Thanks @AgenticSpark for the diagnosis, fix, and regression tests!