hermes - 💡(How to fix) Fix Multi-profile setup: plugins/ and auth.json not shared across HERMES_HOME profiles

Problem

When using Hermes with multiple profiles (e.g. ~/.hermes/profiles/hephaestus/), the plugin loader resolves plugin directories relative to HERMES_HOME. This means:

• Plugins installed in ~/.hermes/plugins/ are not visible to profile-specific gateways running with HERMES_HOME=~/.hermes/profiles/<name>/
• config.yaml with plugins.enabled: [hermes-claude-auth] silently does nothing — no error, no warning, the plugin just doesn't load
• Similarly, auth.json credentials (API keys, OAuth tokens) are profile-local and empty by default — fallback providers also fail

Reproduction

1. Install a plugin globally (~/.hermes/plugins/hermes-claude-auth)
2. Create a second profile: HERMES_HOME=~/.hermes/profiles/myagent/
3. Set plugins.enabled: [hermes-claude-auth] in the profile's config.yaml
4. Start gateway with the profile HERMES_HOME — plugin is silently not loaded, no warning emitted

Expected Behavior

One of:

• A plugins.global_path config option pointing to shared plugin dirs, or
• A fallback that checks ~/.hermes/plugins/ when a listed plugin is not found in the profile-local plugins/ dir, or
• At minimum: a warning log when a plugin listed in plugins.enabled is not found on disk

Current Workaround

mkdir -p ~/.hermes/profiles/myagent/plugins
ln -sf ~/.hermes/plugins/hermes-claude-auth ~/.hermes/profiles/myagent/plugins/hermes-claude-auth
ln -sf ~/.hermes/auth.json ~/.hermes/profiles/myagent/auth.json

Environment

• Hermes: latest main
• OS: Linux (Oracle Cloud, aarch64)
• Multi-profile setup with separate systemd services per profile