feat(FN-2709): migrate Hermes runtime plugin to pi-ai streaming client

- Replace Hermes pi module integration with pi-ai session streaming and updated runtime adapter contracts
- Remove legacy engine guard scaffolding and add hermes-stream-client coverage for streaming behavior
- Rewrite plugin and engine e2e tests to align with the new runtime flow and regenerate dist artifacts
- Update Hermes runtime README and package metadata to document pi-ai execution expectations

plugins/fusion-plugin-hermes-runtime/src/index.ts

@@ -6,6 +6,7 @@
  */
 
 import { definePlugin } from "@fusion/plugin-sdk";
+import { resolveModelConfig } from "./pi-module.js";
 import { HermesRuntimeAdapter } from "./runtime-adapter.js";
 import type {
   FusionPlugin,
@@ -21,14 +22,21 @@ const HERMES_RUNTIME_VERSION = "0.1.0";
 const hermesRuntimeMetadata: PluginRuntimeManifestMetadata = {
   runtimeId: HERMES_RUNTIME_ID,
   name: "Hermes Runtime",
-  description: "Hermes-backed AI session using the user's configured pi provider and model",
+  description: "Hermes raw-model runtime using pi-ai direct streaming",
   version: HERMES_RUNTIME_VERSION,
 };
 
 // ── Hermes Runtime Factory ────────────────────────────────────────────────────
 
-const hermesRuntimeFactory: PluginRuntimeFactory = async () => {
-  return new HermesRuntimeAdapter();
+const hermesRuntimeFactory: PluginRuntimeFactory = async (ctx) => {
+  const config = resolveModelConfig(ctx.settings);
+
+  return new HermesRuntimeAdapter({
+    provider: config.provider,
+    modelId: config.modelId,
+    apiKey: config.apiKey,
+    thinkingLevel: config.thinkingLevel,
+  });
 };
 
 // ── Plugin Definition ─────────────────────────────────────────────────────────
@@ -46,7 +54,8 @@ const plugin: FusionPlugin = definePlugin({
   state: "installed",
   hooks: {
     onLoad: (ctx) => {
-      ctx.logger.info("Hermes Runtime Plugin loaded");
+      const config = resolveModelConfig(ctx.settings);
+      ctx.logger.info(`Hermes Runtime Plugin loaded — using ${config.provider}/${config.modelId}`);
       ctx.emitEvent("hermes-runtime:loaded", {
         runtimeId: HERMES_RUNTIME_ID,
         version: HERMES_RUNTIME_VERSION,