You are generating PHASE 1 of 4 of a lesson — skeleton + primary sources.

Rules:
- Primary sources need REAL 3-8 sentence quotes with attribution. Never "see handout".
- Each primary source needs image_spec and 2+ scaffolding_questions.
- Vocabulary: 6-8 terms (NEVER fewer than 6) with definition + context_sentence.
- lesson_personality: one-line theme (e.g. "Today you're detectives investigating Seneca Falls").
- lesson_format: station_rotation | document_analysis | jigsaw | gallery_walk | socratic_seminar | gradual_release | simulation | lecture_discussion

## Lesson
- Unit: {unit_title}
- Subject: {subject} | Grade: {grade_level}
- Topic: {topic}
- Objective: {objective}
- Duration: {duration_minutes} min
- Standards: {standards}

{teacher_materials}

Respond with ONLY a JSON object (no markdown):

{
    "title": "Lesson Title",
    "subject": "{subject}",
    "grade_level": "{grade_level}",
    "topic": "{topic}",
    "standards": ["standard 1", "standard 2"],
    "objective": "SWBAT ... (observable verb)",
    "duration_minutes": {duration_minutes},
    "vocabulary": [
        {
            "term": "Term",
            "definition": "Student-friendly definition",
            "context_sentence": "Sentence using the term in context",
            "image_spec": "specific image search query"
        }
    ],
    "primary_sources": [
        {
            "id": "source_a",
            "title": "Document Title",
            "source_type": "text_excerpt",
            "content_text": "REAL 3-8 sentence quote from the actual document.",
            "attribution": "Author, Year",
            "image_spec": "Author document year search query",
            "scaffolding_questions": ["Identification question?", "Analysis question?"]
        }
    ],
    "misconceptions": ["What students THINK vs what's true"],
    "prerequisite_skills": ["Skill students need before this lesson"],
    "lesson_format": "station_rotation",
    "lesson_personality": "One-line theme for this lesson",
    "materials_needed": ["Item 1", "Item 2"]
}

Provide 3-4 primary sources and EXACTLY 6-8 vocabulary terms (never fewer than 6).
