fix(agents): initialize ExtensionRunner in embedded mode (#2027)

In pi-coding-agent, ExtensionRunner defaults ctx.model to undefined
until extensionRunner.initialize() is called. Moltbot uses the SDK in
embedded mode (no interactive UI), so compaction hooks that rely on
ctx.model (e.g. compaction-safeguard) would fall back to
"Summary unavailable..." and history would be truncated without a
real summary.

CHANGELOG.md

@@ -40,6 +40,7 @@ Status: beta.
 - **BREAKING:** Gateway auth mode "none" is removed; gateway now requires token/password (Tailscale Serve identity still allowed).
 
 ### Fixes
+- Agents: initialize ExtensionRunner in embedded mode so compaction hooks produce real summaries instead of "Summary unavailable...". (#2027)
 - Security: harden SSH tunnel target parsing to prevent option injection/DoS. (#4001) Thanks @YLChen-007.
 - Security: prevent PATH injection in exec sandbox; harden file serving; pin DNS in URL fetches; verify Twilio webhooks; fix LINE webhook timing-attack edge case; validate Tailscale Serve identity; flag loopback Control UI with auth disabled as critical. (#1616, #1795)
 - Gateway: prevent crashes on transient network errors, suppress AbortError/unhandled rejections, sanitize error responses, clean session locks on exit, and harden reverse proxy handling for unauthenticated proxied connects. (#2980, #2451, #2483, #1795)

src/agents/pi-embedded-runner/run/attempt.ts

@@ -4,7 +4,12 @@ import os from "node:os";
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { AssistantMessage, ImageContent } from "@mariozechner/pi-ai";
 import { streamSimple } from "@mariozechner/pi-ai";
-import { createAgentSession, SessionManager, SettingsManager } from "@mariozechner/pi-coding-agent";
+import {
+  createAgentSession,
+  SessionManager,
+  SettingsManager,
+  type CompactOptions,
+} from "@mariozechner/pi-coding-agent";
 
 import { resolveHeartbeatPrompt } from "../../../auto-reply/heartbeat.js";
 import {
@@ -492,6 +497,74 @@ export async function runEmbeddedAttempt(
       // Force a stable streamFn reference so vitest can reliably mock @mariozechner/pi-ai.
       activeSession.agent.streamFn = streamSimple;
 
+      // IMPORTANT (embedded mode): initialize the pi extension runner.
+      //
+      // In pi-coding-agent, ExtensionRunner defaults `ctx.model` to `undefined` until
+      // `extensionRunner.initialize(...)` is called. Moltbot uses the SDK in embedded
+      // mode (no interactive UI), so without this initialization compaction hooks that
+      // rely on `ctx.model` (e.g. `compaction-safeguard`) will always fall back to
+      // "Summary unavailable..." and history will be truncated without a summary.
+      const extensionRunner = activeSession.extensionRunner;
+      if (extensionRunner) {
+        extensionRunner.initialize(
+          {
+            // Embedded runs don't have a UI; keep UI-dependent actions as safe no-ops.
+            sendMessage: async () => {},
+            sendUserMessage: async () => {},
+            appendEntry: () => {},
+            setSessionName: () => {},
+            getSessionName: () => undefined,
+            setLabel: () => {},
+            getActiveTools: () =>
+              (activeSession.agent.state.tools ?? [])
+                .map((tool) => {
+                  if (!tool) return undefined;
+                  if (typeof tool === "string") return tool;
+                  if (typeof tool === "object" && "name" in tool) {
+                    const name = (tool as { name?: unknown }).name;
+                    return typeof name === "string" ? name : undefined;
+                  }
+                  return undefined;
+                })
+                .filter((name): name is string => typeof name === "string"),
+            getAllTools: () => [],
+            setActiveTools: () => {},
+            setModel: async (model) => {
+              const key = await activeSession.modelRegistry.getApiKey(model);
+              if (!key) return false;
+              await activeSession.setModel(model);
+              return true;
+            },
+            getThinkingLevel: () => activeSession.thinkingLevel,
+            setThinkingLevel: (level) => {
+              activeSession.setThinkingLevel(level);
+            },
+          },
+          {
+            // Provide live model + context access for extensions.
+            getModel: () => activeSession.agent.state.model,
+            isIdle: () => true,
+            abort: () => {
+              void activeSession.abort();
+            },
+            hasPendingMessages: () => false,
+            shutdown: () => {},
+            getContextUsage: () => activeSession.getContextUsage(),
+            compact: (options?: CompactOptions) => {
+              void (async () => {
+                try {
+                  const result = await activeSession.compact(options?.customInstructions);
+                  options?.onComplete?.(result);
+                } catch (error) {
+                  const err = error instanceof Error ? error : new Error(String(error));
+                  options?.onError?.(err);
+                }
+              })();
+            },
+          },
+        );
+      }
+
       applyExtraParamsToAgent(
         activeSession.agent,
         params.config,