diff --git a/src/infra/heartbeat-events.test.ts b/src/infra/heartbeat-events.test.ts
new file mode 100644
index 00000000000..d1583f8080a
--- /dev/null
+++ b/src/infra/heartbeat-events.test.ts
@@ -0,0 +1,59 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  emitHeartbeatEvent,
+  getLastHeartbeatEvent,
+  onHeartbeatEvent,
+  resolveIndicatorType,
+} from "./heartbeat-events.js";
+
+describe("resolveIndicatorType", () => {
+  it("maps heartbeat statuses to indicator types", () => {
+    expect(resolveIndicatorType("ok-empty")).toBe("ok");
+    expect(resolveIndicatorType("ok-token")).toBe("ok");
+    expect(resolveIndicatorType("sent")).toBe("alert");
+    expect(resolveIndicatorType("failed")).toBe("error");
+    expect(resolveIndicatorType("skipped")).toBeUndefined();
+  });
+});
+
+describe("heartbeat events", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-01-09T12:00:00Z"));
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("stores the last event and timestamps emitted payloads", () => {
+    emitHeartbeatEvent({ status: "sent", to: "+123", preview: "ping" });
+
+    expect(getLastHeartbeatEvent()).toEqual({
+      ts: 1767960000000,
+      status: "sent",
+      to: "+123",
+      preview: "ping",
+    });
+  });
+
+  it("delivers events to listeners, isolates listener failures, and supports unsubscribe", () => {
+    const seen: string[] = [];
+    const unsubscribeFirst = onHeartbeatEvent((evt) => {
+      seen.push(`first:${evt.status}`);
+    });
+    onHeartbeatEvent(() => {
+      throw new Error("boom");
+    });
+    const unsubscribeThird = onHeartbeatEvent((evt) => {
+      seen.push(`third:${evt.status}`);
+    });
+
+    emitHeartbeatEvent({ status: "ok-empty" });
+    unsubscribeFirst();
+    unsubscribeThird();
+    emitHeartbeatEvent({ status: "failed" });
+
+    expect(seen).toEqual(["first:ok-empty", "third:ok-empty"]);
+  });
+});
diff --git a/src/infra/outbound/target-normalization.test.ts b/src/infra/outbound/target-normalization.test.ts
new file mode 100644
index 00000000000..c8e6ea7e124
--- /dev/null
+++ b/src/infra/outbound/target-normalization.test.ts
@@ -0,0 +1,142 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const normalizeChannelIdMock = vi.hoisted(() => vi.fn());
+const getChannelPluginMock = vi.hoisted(() => vi.fn());
+const getActivePluginRegistryVersionMock = vi.hoisted(() => vi.fn());
+
+vi.mock("../../channels/plugins/index.js", () => ({
+  normalizeChannelId: (...args: unknown[]) => normalizeChannelIdMock(...args),
+  getChannelPlugin: (...args: unknown[]) => getChannelPluginMock(...args),
+}));
+
+vi.mock("../../plugins/runtime.js", () => ({
+  getActivePluginRegistryVersion: (...args: unknown[]) =>
+    getActivePluginRegistryVersionMock(...args),
+}));
+
+import {
+  buildTargetResolverSignature,
+  normalizeChannelTargetInput,
+  normalizeTargetForProvider,
+} from "./target-normalization.js";
+
+describe("normalizeChannelTargetInput", () => {
+  it("trims raw target input", () => {
+    expect(normalizeChannelTargetInput("  channel:C1  ")).toBe("channel:C1");
+  });
+});
+
+describe("normalizeTargetForProvider", () => {
+  beforeEach(() => {
+    normalizeChannelIdMock.mockReset();
+    getChannelPluginMock.mockReset();
+    getActivePluginRegistryVersionMock.mockReset();
+  });
+
+  it("returns undefined for missing or blank raw input", () => {
+    expect(normalizeTargetForProvider("telegram")).toBeUndefined();
+    expect(normalizeTargetForProvider("telegram", "   ")).toBeUndefined();
+  });
+
+  it("falls back to trimmed input when the provider is unknown or has no normalizer", () => {
+    normalizeChannelIdMock.mockReturnValueOnce(null);
+    expect(normalizeTargetForProvider("unknown", "  raw-id  ")).toBe("raw-id");
+
+    normalizeChannelIdMock.mockReturnValueOnce("telegram");
+    getActivePluginRegistryVersionMock.mockReturnValueOnce(1);
+    getChannelPluginMock.mockReturnValueOnce(undefined);
+    expect(normalizeTargetForProvider("telegram", "  raw-id  ")).toBe("raw-id");
+  });
+
+  it("uses the cached target normalizer until the plugin registry version changes", () => {
+    const firstNormalizer = vi.fn((raw: string) => raw.trim().toUpperCase());
+    const secondNormalizer = vi.fn((raw: string) => `next:${raw.trim()}`);
+    normalizeChannelIdMock.mockReturnValue("telegram");
+    getActivePluginRegistryVersionMock
+      .mockReturnValueOnce(10)
+      .mockReturnValueOnce(10)
+      .mockReturnValueOnce(11);
+    getChannelPluginMock
+      .mockReturnValueOnce({
+        messaging: { normalizeTarget: firstNormalizer },
+      })
+      .mockReturnValueOnce({
+        messaging: { normalizeTarget: secondNormalizer },
+      });
+
+    expect(normalizeTargetForProvider("telegram", "  abc  ")).toBe("ABC");
+    expect(normalizeTargetForProvider("telegram", "  def  ")).toBe("DEF");
+    expect(normalizeTargetForProvider("telegram", "  ghi  ")).toBe("next:ghi");
+
+    expect(getChannelPluginMock).toHaveBeenCalledTimes(2);
+    expect(firstNormalizer).toHaveBeenCalledTimes(2);
+    expect(secondNormalizer).toHaveBeenCalledTimes(1);
+  });
+
+  it("returns undefined when the provider normalizer resolves to an empty value", () => {
+    normalizeChannelIdMock.mockReturnValueOnce("telegram");
+    getActivePluginRegistryVersionMock.mockReturnValueOnce(20);
+    getChannelPluginMock.mockReturnValueOnce({
+      messaging: {
+        normalizeTarget: () => "",
+      },
+    });
+
+    expect(normalizeTargetForProvider("telegram", "  raw-id  ")).toBeUndefined();
+  });
+});
+
+describe("buildTargetResolverSignature", () => {
+  beforeEach(() => {
+    getChannelPluginMock.mockReset();
+  });
+
+  it("builds stable signatures from resolver hint and looksLikeId source", () => {
+    const looksLikeId = (value: string) => value.startsWith("C");
+    getChannelPluginMock.mockReturnValueOnce({
+      messaging: {
+        targetResolver: {
+          hint: "Use channel id",
+          looksLikeId,
+        },
+      },
+    });
+
+    const first = buildTargetResolverSignature("slack");
+    getChannelPluginMock.mockReturnValueOnce({
+      messaging: {
+        targetResolver: {
+          hint: "Use channel id",
+          looksLikeId,
+        },
+      },
+    });
+    const second = buildTargetResolverSignature("slack");
+
+    expect(first).toBe(second);
+  });
+
+  it("changes when resolver metadata changes", () => {
+    getChannelPluginMock.mockReturnValueOnce({
+      messaging: {
+        targetResolver: {
+          hint: "Use channel id",
+          looksLikeId: (value: string) => value.startsWith("C"),
+        },
+      },
+    });
+    const first = buildTargetResolverSignature("slack");
+
+    getChannelPluginMock.mockReturnValueOnce({
+      messaging: {
+        targetResolver: {
+          hint: "Use user id",
+          looksLikeId: (value: string) => value.startsWith("U"),
+        },
+      },
+    });
+    const second = buildTargetResolverSignature("slack");
+
+    expect(first).not.toBe(second);
+  });
+});
diff --git a/src/infra/outbound/tool-payload.test.ts b/src/infra/outbound/tool-payload.test.ts
new file mode 100644
index 00000000000..08629089618
--- /dev/null
+++ b/src/infra/outbound/tool-payload.test.ts
@@ -0,0 +1,42 @@
+import { describe, expect, it } from "vitest";
+import { extractToolPayload } from "./tool-payload.js";
+
+describe("extractToolPayload", () => {
+  it("prefers explicit details payloads", () => {
+    expect(
+      extractToolPayload({
+        details: { ok: true },
+        content: [{ type: "text", text: '{"ignored":true}' }],
+      } as never),
+    ).toEqual({ ok: true });
+  });
+
+  it("parses JSON text blocks from tool content", () => {
+    expect(
+      extractToolPayload({
+        content: [
+          { type: "image", url: "https://example.com/a.png" },
+          { type: "text", text: '{"ok":true,"count":2}' },
+        ],
+      } as never),
+    ).toEqual({ ok: true, count: 2 });
+  });
+
+  it("falls back to raw text, then content, then the whole result", () => {
+    expect(
+      extractToolPayload({
+        content: [{ type: "text", text: "not json" }],
+      } as never),
+    ).toBe("not json");
+
+    const content = [{ type: "image", url: "https://example.com/a.png" }];
+    expect(
+      extractToolPayload({
+        content,
+      } as never),
+    ).toBe(content);
+
+    const result = { status: "ok" };
+    expect(extractToolPayload(result as never)).toBe(result);
+  });
+});