We need to output valid JSON with fields: seo_title, summary, key_entities, expert_faq, internal_link_anchor, primary_keyword, secondary_keywords, content_type.

Constraints: summary must be 180-250 words total across 3-4 paragraphs separated by \n\n. Each paragraph 45-65 words. Must bold 3-5 key details across whole summary using double asterisks. Must not use banned words etc. Must not use markdown formatting except double asterisks for bold. Must not use code fences. Must output only JSON.

We need to count words precisely. Let's craft summary 180-250 words. Let's aim for 200 words.

Structure: 3 paragraphs of ~65 words each? But each paragraph must be 45-65 words. So we can do 3 paragraphs of about 65 words each = 195 words total, within range.

Paragraph 1: talk about engineers at BAE using VR cave to test engine digitally, funding boost. Paragraph 2: talk about funding amount £8.6bn, partners Italy Leonardo, Japan Mitsubishi, interim contract, relief. Paragraph 3: talk about demonstrator Tempest, testing schedule, significance, concluding statement.

We need to bold 3-5 key details across whole summary. Choose bold terms: BAE Systems, £8.6bn, Tempest. Maybe also Global Combat Air Programme. That's 3-5 bold terms. Let's bold BAE Systems, £8.6bn, Tempest, Global Combat Air Programme (that's 4). Ensure we bold only those terms, not generic words.

We must ensure bold formatting uses double asterisks around the term exactly. Eg BAE Systems. Must not bold extra words.

We must not use banned words. Avoid filler words like "additionally". Avoid "pivotal". Avoid "key". Avoid "significant". Avoid "major". Avoid "critical"? Actually "critical" is not banned? It's not in banned list. But we need to be careful with "critical" maybe okay. The banned list includes "key"? Yes "key" is banned. So cannot use "key". Must avoid "key". So we cannot say "key details". Must avoid that word. Also "critical" is not banned. It's okay. But we mu