fix(agent): raise tool rounds and ease calendar creates

Local models were burning the 8-round budget on simple event adds.
Raise the limit, resolve calendars by name/default, and inject the
household clock so relative dates work.

tests/unit/agent-chat.test.ts

@@ -83,6 +83,36 @@ describe("runAgentChat", () => {
     assert.equal(result.message.role, "assistant");
     assert.ok(result.message.content.length > 0);
   });
+
+  it("appends runtime clock context to the system prompt", async () => {
+    const original = process.env.HOUSEHOLD_TIMEZONE;
+    process.env.HOUSEHOLD_TIMEZONE = "America/Chicago";
+
+    let systemContent = "";
+    const result = await runAgentChat({
+      messages: [{ role: "user", content: "hello" }],
+      request: new Request("http://localhost:3000/api/agent/chat"),
+      systemPrompt: "You are a pirate.",
+      llm: {
+        async chatCompletion(request) {
+          const system = request.messages.find((message) => message.role === "system");
+          systemContent = typeof system?.content === "string" ? system.content : "";
+          return {
+            message: { role: "assistant", content: "Ahoy" },
+            finishReason: "stop",
+          };
+        },
+      },
+    });
+
+    assert.equal(result.message.content, "Ahoy");
+    assert.match(systemContent, /^You are a pirate\./);
+    assert.match(systemContent, /Current time:/);
+    assert.match(systemContent, /America\/Chicago/);
+
+    if (original === undefined) delete process.env.HOUSEHOLD_TIMEZONE;
+    else process.env.HOUSEHOLD_TIMEZONE = original;
+  });
 });
 
 it("passes a model override to the OpenAI-compatible client", async () => {

tests/unit/agent-tools-runtime.test.ts

@@ -0,0 +1,117 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import { appendAgentRuntimeContext, resolveHouseholdTimezone } from "../../src/modules/agent/tools";
+import { createApiToolExecutor } from "../../src/modules/agent/tool-executor";
+
+describe("appendAgentRuntimeContext", () => {
+  it("appends current time and timezone to the prompt", () => {
+    const original = process.env.HOUSEHOLD_TIMEZONE;
+    process.env.HOUSEHOLD_TIMEZONE = "America/Chicago";
+
+    const now = new Date("2026-07-09T14:30:00.000Z");
+    const result = appendAgentRuntimeContext("Be helpful.", now);
+
+    assert.match(result, /^Be helpful\./);
+    assert.match(result, /Current time:/);
+    assert.match(result, /America\/Chicago/);
+    assert.match(result, /2026-07-09T14:30:00\.000Z/);
+    assert.match(result, /Resolve relative dates from this clock/);
+
+    if (original === undefined) delete process.env.HOUSEHOLD_TIMEZONE;
+    else process.env.HOUSEHOLD_TIMEZONE = original;
+  });
+});
+
+describe("resolveHouseholdTimezone", () => {
+  it("prefers HOUSEHOLD_TIMEZONE over TZ", () => {
+    const originalHousehold = process.env.HOUSEHOLD_TIMEZONE;
+    const originalTz = process.env.TZ;
+    process.env.HOUSEHOLD_TIMEZONE = "America/New_York";
+    process.env.TZ = "UTC";
+
+    assert.equal(resolveHouseholdTimezone(), "America/New_York");
+
+    if (originalHousehold === undefined) delete process.env.HOUSEHOLD_TIMEZONE;
+    else process.env.HOUSEHOLD_TIMEZONE = originalHousehold;
+    if (originalTz === undefined) delete process.env.TZ;
+    else process.env.TZ = originalTz;
+  });
+});
+
+describe("create_event calendar resolution", () => {
+  it("uses the first calendar when calendarId and calendarName are omitted", async () => {
+    const originalFetch = globalThis.fetch;
+    const posts: Array<{ path: string; body: unknown }> = [];
+
+    globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+      const url = String(input);
+      if (url.endsWith("/api/v1/calendars") && (!init?.method || init.method === "GET")) {
+        return Response.json([
+          { id: "cal-1", name: "Family" },
+          { id: "cal-2", name: "Work" },
+        ]);
+      }
+      if (url.endsWith("/api/v1/events") && init?.method === "POST") {
+        const body = JSON.parse(String(init.body));
+        posts.push({ path: url, body });
+        return Response.json({ id: "evt-1", ...body }, { status: 201 });
+      }
+      return new Response("not found", { status: 404 });
+    }) as typeof fetch;
+
+    const execute = createApiToolExecutor(new Request("http://localhost:3000/api/agent/chat"));
+    const result = JSON.parse(
+      await execute(
+        "create_event",
+        JSON.stringify({
+          title: "Dentist",
+          startAt: "2026-07-10T15:00:00.000Z",
+          endAt: "2026-07-10T16:00:00.000Z",
+        }),
+      ),
+    ) as { status: number; body: { calendarId?: string } };
+
+    assert.equal(result.status, 201);
+    assert.equal(result.body.calendarId, "cal-1");
+    assert.equal(posts.length, 1);
+
+    globalThis.fetch = originalFetch;
+  });
+
+  it("matches calendarName case-insensitively", async () => {
+    const originalFetch = globalThis.fetch;
+
+    globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+      const url = String(input);
+      if (url.endsWith("/api/v1/calendars") && (!init?.method || init.method === "GET")) {
+        return Response.json([
+          { id: "cal-1", name: "Family" },
+          { id: "cal-2", name: "Work" },
+        ]);
+      }
+      if (url.endsWith("/api/v1/events") && init?.method === "POST") {
+        const body = JSON.parse(String(init.body));
+        return Response.json({ id: "evt-1", ...body }, { status: 201 });
+      }
+      return new Response("not found", { status: 404 });
+    }) as typeof fetch;
+
+    const execute = createApiToolExecutor(new Request("http://localhost:3000/api/agent/chat"));
+    const result = JSON.parse(
+      await execute(
+        "create_event",
+        JSON.stringify({
+          calendarName: "work",
+          title: "Standup",
+          startAt: "2026-07-10T15:00:00.000Z",
+          endAt: "2026-07-10T15:30:00.000Z",
+        }),
+      ),
+    ) as { status: number; body: { calendarId?: string } };
+
+    assert.equal(result.status, 201);
+    assert.equal(result.body.calendarId, "cal-2");
+
+    globalThis.fetch = originalFetch;
+  });
+});