fix(cli): skip npm lifecycle scripts during agent-browser post-setup

[liuhao1024]

What does this PR do?

Adds --ignore-scripts to the npm install command in _run_post_setup() to prevent agent-browser's postinstall script from replacing the global npm symlink with a local node_modules/ path that gets destroyed on the next hermes update.

Related Issue

Fixes #48521

Type of Change

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

Changes Made

• hermes_cli/tools_config.py: Added --ignore-scripts flag to the npm install command in _run_post_setup() for the agent_browser/browserbase post-setup path. This prevents agent-browser's fixUnixSymlink() postinstall from overwriting the global npm symlink (e.g. /opt/homebrew/bin/agent-browser) to point at the local node_modules/ binary, which disappears on the next update.
• tests/hermes_cli/test_tools_config.py: Added test_agent_browser_post_setup_passes_ignore_scripts — verifies that --ignore-scripts is present in the npm install command when _run_post_setup('agent_browser') runs.

How to Test

1. Install agent-browser globally: npm install -g agent-browser@0.27.1
2. Verify the global symlink points to the global install: ls -la $(which agent-browser) — should point to /opt/homebrew/lib/node_modules/agent-browser/...
3. Run hermes update (or any command that triggers _run_post_setup("agent_browser"))
4. Verify the global symlink is unchanged: ls -la $(which agent-browser) — should still point to the global install path
5. Verify browser tools still work: agent-browser --version
6. Run the regression test: python -m pytest tests/hermes_cli/test_tools_config.py::test_agent_browser_post_setup_passes_ignore_scripts -xvs

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Code Intelligence

⚠️ GitNexus unavailable — grep-based fallback used.

• Checked files/symbols: _run_post_setup in hermes_cli/tools_config.py (callers: 4 call sites in tools_config.py)
• Blast radius: LOW — only affects the npm install command in _run_post_setup, which is a setup/installation path
• Related patterns: fixUnixSymlink() in agent-browser/scripts/postinstall.js is the upstream root cause; --ignore-scripts is the standard npm flag to suppress lifecycle scripts