add built-in herdr integration

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 
+- Added built-in Herdr integration that reports agent lifecycle state to Herdr panes automatically, without requiring `herdr integration install pi`.
 - Changed Escape to interrupt active work with a visible abort notice, double Escape to open the session tree from an empty prompt or clear an idle draft, and `?` to show shortcuts ([ENG-4489](https://linear.app/primeintellect/issue/ENG-4489/rewire-prime-agent-shortcuts-to-match-claude-code-flow)).
 - Changed new-chat guidance to show concise shell, command, file, and shortcut hints, with Agents View first and `? for shortcuts` after the model and effort ([ENG-4489](https://linear.app/primeintellect/issue/ENG-4489/rewire-prime-agent-shortcuts-to-match-claude-code-flow)).
 - Changed `?` shortcut help to appear as a temporary compact panel below the transcript, while `/hotkeys` shows the full reference without Ctrl+Z ([ENG-4489](https://linear.app/primeintellect/issue/ENG-4489/rewire-prime-agent-shortcuts-to-match-claude-code-flow)).

packages/coding-agent/src/core/agent-session-services.ts

@@ -7,6 +7,7 @@ import type { AgentObserveController } from "./agent-observe.js";
 import { installAgentTraceUpload } from "./agent-traces.js";
 import { AuthStorage } from "./auth-storage.js";
 import type { AgentRlmHeartbeatController } from "./cron-jobs.js";
+import { createHerdrAgentStateExtension } from "./extensions/builtin/herdr-agent-state.js";
 import type { SessionStartEvent, ToolDefinition } from "./extensions/index.js";
 import { McpManager } from "./mcp/mcp-manager.js";
 import { ModelRegistry } from "./model-registry.js";
@@ -43,6 +44,13 @@ export interface CreateAgentSessionServicesOptions {
 	modelRegistry?: ModelRegistry;
 	extensionFlagValues?: Map<string, boolean | string>;
 	resourceLoaderOptions?: Omit<DefaultResourceLoaderOptions, "cwd" | "agentDir" | "settingsManager">;
+	/**
+	 * Skip the built-in Herdr reporter for these services. Set for RLM subagent
+	 * runtimes: they inherit the parent's HERDR_* pane identity, so their own
+	 * reporter would race the parent's on the same pane and a subagent quit
+	 * would release the pane while the parent is still running.
+	 */
+	noBuiltinHerdrReporter?: boolean;
 }
 
 export interface AgentSessionCreationOptions {
@@ -167,8 +175,21 @@ export async function createAgentSessionServices(
 	// refresh() resets the OAuth registry to built-ins; re-add user MCP providers too.
 	modelRegistry.setOnOAuthProvidersReset(() => mcpManager.registerUserProviders());
 
-	const resourceLoader = new DefaultResourceLoader({
+	const userExtensionFactories = options.resourceLoaderOptions?.extensionFactories ?? [];
+	// The built-in Herdr reporter defers to Herdr's own file-based integration
+	// when the loader actually loaded it; two reporters would race on the same
+	// pane. Deferral is late-bound to the loader's loaded paths (inline
+	// factories run after file extensions load), so a file that exists but is
+	// disabled or never discovered does not silence the built-in.
+	// noExtensions is a full opt-out: it disables the built-in reporter too,
+	// not just discovered extension files.
+	const skipHerdrReporter = options.noBuiltinHerdrReporter || options.resourceLoaderOptions?.noExtensions;
+	const builtinExtensionFactories = skipHerdrReporter
+		? []
+		: [createHerdrAgentStateExtension(() => resourceLoader.getLoadedExtensionPaths())];
+	const resourceLoader: DefaultResourceLoader = new DefaultResourceLoader({
 		...(options.resourceLoaderOptions ?? {}),
+		extensionFactories: [...builtinExtensionFactories, ...userExtensionFactories],
 		cwd,
 		agentDir,
 		settingsManager,