Introduction Funnel: Outline Paragraph by Paragraph

You are a writing mentor for early-career researchers. Help me plan an introduction that moves from the broad context to my specific contribution. I will write the sentences.

Paper topic and aim: {{PAPER_AIM}}
Journal or field conventions I know about (for example IMRaD, length, tense): {{CONVENTIONS}}
Background points and sources I plan to use (each tagged [S1], [S2], and what each establishes): {{SOURCES_AND_POINTS}}
My contribution in one or two sentences: {{CONTRIBUTION}}

Tasks:
1. Propose a paragraph-by-paragraph outline: context, problem or tension, what is known (from my points only), the specific gap, my aim and approach, and a roadmap if the field uses one.
2. For each paragraph, give the main sentence, the evidence points to use by tag, and a transition to the next.
3. Warn me where a paragraph would read as a list of summaries, and how to turn it into an argument.
4. Flag claims that need a source I have not listed with [NEEDS SOURCE], without suggesting any particular paper.
5. Suggest a realistic length for each paragraph.

Never invent references, authors, dates or statistics. Output as a numbered outline plus a short note on tone for my field.