Apply demo-activity-bot: Bruno, the synthetic public-walk generator

Adds a background demo user (`bruno`) plus two pg-boss jobs that generate
public trekking routes and activities in inner Berlin and prune them
after 14 days. Disabled by default everywhere; flip `DEMO_BOT_ENABLED`
only in prod.

- Schema: `synthetic` boolean on routes + activities
- `ensureDemoUser()` idempotent insert + badge on /users/bruno
- Generation gate: 07-21 Berlin local, p=0.12, 40-route cap in 14d
- Initial 4-walk backfill on first enable; retention via daily prune
- Prometheus gauges `demo_bot_synthetic_routes_total` / `_activities_total`
- Unit + DB-gated integration + E2E tests

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/journal/app/lib/demo-bot.test.ts

@@ -0,0 +1,119 @@
+import { describe, it, expect } from "vitest";
+import {
+  berlinHour,
+  loadRegion,
+  pickEndpoints,
+  shouldWalkNow,
+  templateDescription,
+  templateName,
+} from "./demo-bot.server.ts";
+
+describe("pickEndpoints", () => {
+  const bbox: [number, number, number, number] = [13.25, 52.45, 13.55, 52.60];
+
+  it("returns points inside the bbox", () => {
+    for (let i = 0; i < 20; i++) {
+      const { start, end } = pickEndpoints(bbox);
+      expect(start[0]).toBeGreaterThanOrEqual(bbox[0]);
+      expect(start[0]).toBeLessThanOrEqual(bbox[2]);
+      expect(start[1]).toBeGreaterThanOrEqual(bbox[1]);
+      expect(start[1]).toBeLessThanOrEqual(bbox[3]);
+      expect(end[0]).toBeGreaterThanOrEqual(bbox[0]);
+      expect(end[0]).toBeLessThanOrEqual(bbox[2]);
+      expect(end[1]).toBeGreaterThanOrEqual(bbox[1]);
+      expect(end[1]).toBeLessThanOrEqual(bbox[3]);
+    }
+  });
+
+  it("produces distinct endpoints", () => {
+    for (let i = 0; i < 10; i++) {
+      const { start, end } = pickEndpoints(bbox);
+      expect(start).not.toEqual(end);
+    }
+  });
+});
+
+describe("templateName / templateDescription", () => {
+  it("returns non-empty strings in both locales", () => {
+    const d = new Date("2026-04-17T09:00:00Z");
+    expect(templateName(d, "en").length).toBeGreaterThan(0);
+    expect(templateName(d, "de").length).toBeGreaterThan(0);
+    expect(templateDescription(d, "en").length).toBeGreaterThan(0);
+    expect(templateDescription(d, "de").length).toBeGreaterThan(0);
+  });
+
+  it("returns different entries for different seeds", () => {
+    const a = templateName(new Date("2026-04-17T09:00:00Z"), "en");
+    const b = templateName(new Date("2026-04-18T10:01:00Z"), "en");
+    // Not strictly required, but with 12 entries and different seeds it
+    // would be surprising if every pair collided — this is a smoke check.
+    expect(typeof a).toBe("string");
+    expect(typeof b).toBe("string");
+  });
+});
+
+describe("loadRegion", () => {
+  const envKey = "DEMO_BOT_REGION";
+
+  it("falls back to the default Berlin bbox when unset", () => {
+    const saved = process.env[envKey];
+    delete process.env[envKey];
+    try {
+      const r = loadRegion();
+      expect(r.bbox).toEqual([13.25, 52.45, 13.55, 52.60]);
+    } finally {
+      if (saved !== undefined) process.env[envKey] = saved;
+    }
+  });
+
+  it("parses a valid JSON override", () => {
+    const saved = process.env[envKey];
+    process.env[envKey] = JSON.stringify({ bbox: [0, 0, 1, 1] });
+    try {
+      const r = loadRegion();
+      expect(r.bbox).toEqual([0, 0, 1, 1]);
+    } finally {
+      if (saved === undefined) delete process.env[envKey];
+      else process.env[envKey] = saved;
+    }
+  });
+
+  it("falls back on invalid JSON", () => {
+    const saved = process.env[envKey];
+    process.env[envKey] = "{not json";
+    try {
+      const r = loadRegion();
+      expect(r.bbox).toEqual([13.25, 52.45, 13.55, 52.60]);
+    } finally {
+      if (saved === undefined) delete process.env[envKey];
+      else process.env[envKey] = saved;
+    }
+  });
+});
+
+describe("shouldWalkNow", () => {
+  // 10:00 Berlin ≈ 08:00 UTC in winter / 09:00 summer. Both are inside 07-21.
+  const berlinMidday = new Date("2026-06-17T10:00:00Z");
+  // 03:00 Berlin ≈ 01:00 UTC summer — outside the window.
+  const berlinNight = new Date("2026-06-17T01:00:00Z");
+
+  it("rejects times outside the 07-21 window regardless of the random roll", () => {
+    expect(shouldWalkNow(berlinNight, () => 0)).toBe(false);
+  });
+
+  it("accepts inside the window when the random roll succeeds", () => {
+    expect(shouldWalkNow(berlinMidday, () => 0)).toBe(true);
+  });
+
+  it("rejects inside the window when the random roll fails", () => {
+    expect(shouldWalkNow(berlinMidday, () => 0.99)).toBe(false);
+  });
+});
+
+describe("berlinHour", () => {
+  it("reports a plausible hour", () => {
+    const h = berlinHour(new Date("2026-06-17T10:00:00Z"));
+    expect(h).toBeGreaterThanOrEqual(0);
+    expect(h).toBeLessThanOrEqual(23);
+  });
+});