release: bump Hermes Agent plugin from 0.6.0 to 0.12.0 (latest)

[MCERQUA]

Priority: HIGH for next release.

Currently pinned at `hermes_version: 0.6.0` in `plugins/hermes-agent/plugin.json`. Latest is `0.12.0` (released 2026-04-30 by Nous Research).

That's six minor version bumps of upstream improvements — likely affects the 14 inference providers, voice integration, memory, and skill auto-generation features the plugin advertises.

File to update

• `plugins/hermes-agent/plugin.json` — `hermes_version` field

Pre-merge checklist

• Read Nous Research Hermes Agent v0.7→v0.12 changelogs
• Verify our 14-provider config matrix still works
• Voice integration smoke test (STT + LLM + TTS roundtrip)
• Test sub-agent creation path on test-dev
• Confirm no breaking config schema changes between 0.6 → 0.12