feat(hermes): add current plugin and MCP integration

.hermes-plugin/README.md

@@ -0,0 +1,73 @@
+# Context Mode for Hermes Agent
+
+This Hermes plugin adds proactive Context Mode routing and a bounded fallback
+for oversized native tool results. It uses the public Hermes plugin API and the
+Python standard library only.
+
+## Requirements
+
+- Hermes Agent with the current Python plugin hooks
+- Node.js 22.5 or later, or Bun
+- The Context Mode MCP server registered under the name `context-mode`
+
+Hermes registers that server's tools as `mcp__context_mode__ctx_*`.
+
+## Install
+
+Register the MCP server:
+
+```bash
+hermes mcp add context-mode --command npx --args -y context-mode
+```
+
+Copy the plugin on Linux, macOS, or WSL:
+
+```bash
+mkdir -p ~/.hermes/plugins/hermes-context-mode
+cp .hermes-plugin/plugin.yaml .hermes-plugin/__init__.py ~/.hermes/plugins/hermes-context-mode/
+```
+
+Copy the plugin in PowerShell:
+
+```powershell
+$target = Join-Path $HOME ".hermes/plugins/hermes-context-mode"
+New-Item -ItemType Directory -Force $target | Out-Null
+Copy-Item .hermes-plugin/plugin.yaml, .hermes-plugin/__init__.py $target -Force
+```
+
+Enable it in `~/.hermes/config.yaml`:
+
+```yaml
+plugins:
+  enabled:
+    - hermes-context-mode
+```
+
+Restart Hermes. For a gateway install, restart the gateway process. Confirm the
+MCP connection with `hermes mcp test context-mode`, then ask Hermes for
+`ctx stats`.
+
+## Behavior
+
+| Hook | Behavior |
+|---|---|
+| `pre_tool_call` | Blocks known high-output terminal fetch/build commands using Hermes' `{"action":"block","message":"..."}` contract. |
+| `transform_tool_result` | Writes eligible outputs larger than 3 KiB to a collision-safe UTF-8 file and returns a compact pointer. |
+| `pre_llm_call` | Injects current `mcp__context_mode__ctx_*` routing guidance once per session. |
+| `on_session_start` | Initializes bounded per-session metrics. |
+| `on_session_end` | Persists a snapshot at Hermes' per-turn boundary without destroying session state. |
+| `on_session_finalize` | Persists and releases state when Hermes tears down the session. |
+
+Generated data stays under
+`~/.hermes/plugins/hermes-context-mode/` (or `$HERMES_HOME/plugins/...`):
+
+```text
+metrics.db
+sandbox/
+```
+
+Hermes plugin API: <https://hermes-agent.nousresearch.com/docs/user-guide/features/plugins>
+
+Hermes hook contracts: <https://hermes-agent.nousresearch.com/docs/user-guide/features/hooks>
+
+Hermes MCP configuration: <https://hermes-agent.nousresearch.com/docs/user-guide/features/mcp>