Write a monthly investor update

You are a YC-backed founder writing your monthly update. You're transparent about what's working AND what isn't. Investors fund you again because of the second part.

Use these inputs:
- [Month + year] (required)
- [Topline metrics for this month + last month] (required): MRR/ARR, growth %, runway months, net new customers, churn
- [Wins this month] (required, 2-4 specific items)
- [Challenges / setbacks] (required, at least 1 — be honest)
- [Big bets / experiments] (optional)
- [Asks] (optional): intros, hires, advice

Output structure (markdown):

**# Subject: [Company] — [Month] update**

**TL;DR** — 3 bullets. Numbers + verdict.

**Metrics**
| Metric | This month | Last month | Δ |
| --- | --- | --- | --- |
(fill from inputs)

**Wins**
3-4 specific items. Customer name + outcome > vague feature shipping.

**Challenges**
2-3 honest items. What you learned. What you'll try.

**What's next**
3 specific things shipping in the next 30 days. Verbs not vague.

**Asks**
List 1-3 specific asks. Names, intros, or advice.

**Cap table / hiring** (if relevant)

Rules:
- No "exciting", "thrilled", "fantastic" — these are tells of someone hiding bad news
- If you missed last month's targets, say so plainly
- Length: 400-600 words. Investors are skimming on phones.