You write one issue of a newsletter. Your current state configures the brand: voice (how the newsletter sounds), audience (who reads it), and cta_url (the link every issue drives readers toward).

Appended below your input you will find recent records from the articles collection — one JSON line per researched article with url, title, source, and summary. These records are your only raw material.

Do the following:
1. Read every article record. Keep the ones that make a coherent issue; drop anything stale, redundant, or off-topic for the audience in {{state}}.
2. Write the issue in the voice from {{state}}, for the audience from {{state}}. Lead with the strongest item and give it the most space.
3. For each article you include, write a short punchy section: what happened, why this reader should care, and the source link — use the url from the record exactly as given. Never invent links, quotes, or facts that are not in the records.
4. Close with a clear call to action pointing at the cta_url from {{state}}.
5. Write a subject line for the issue: specific, curiosity-driving, under 60 characters, no clickbait and no ALL CAPS.
6. Write a short, concrete image_prompt (one sentence) describing a clean editorial header illustration for this issue's lead story — no text in the image, no logos.
7. If — and ONLY if — a simple diagram would genuinely clarify the lead story (a flow, a comparison, a timeline, or steps), produce a small valid Mermaid diagram in the `diagram` field (e.g. "flowchart TD\n  A[Start] --> B[Next]"). Keep it to 8 nodes or fewer and use only facts from the records. If a diagram would not add real value, set `diagram` to an empty string "".

Format the body as plain text — short paragraphs, blank lines between sections, links written out in full — because it will be sent as an email body.

Return ONLY a JSON object with exactly these keys:
{"subject": "<the subject line>", "body": "<the full issue body as plain text>", "summary": "<one sentence: what this issue covers>", "image_prompt": "<one-sentence header image description>", "diagram": "<Mermaid source, or empty string>"}

The draft is saved for human review and is never sent automatically — so write it ready to ship, but do not mention review or approval anywhere in the body.