Add the Interview Q&A quote template (quote-interview) #285

Part of #5. For interview posts that pull out one question and its answer.

Idea
The question at the top in the accent color, after a small "Q" mark ("What would you tell yourself on day one?"). Under it, the answer large, after an "A" mark ("Ship the small version first, then listen."). The person's name and role sit at the bottom ("Priya Raman, Staff Engineer at Acme"), with the site name on the other side.

Template details

• File: src/templates/quote/interview.ts, id quote-interview
• Fields: question (text, optional, default "What would you tell yourself on day one?"), answer (textarea, required, default "Ship the small version first, then listen."), commonFields.author (the person, default "Priya Raman"), role (text, optional, default "Staff Engineer at Acme"), commonFields.siteName, commonFields.bgColor, commonFields.accentColor, commonFields.textColor

Where to look

• Closest reference: src/templates/quote/centered-serif.ts (a quote with the author and their title), src/templates/quote/speech-bubble.ts (a quote with the author below)

Acceptance criteria

• Long questions and answers shrink with autoFontSize() and then truncate, and an empty question, role, author or site name (or only spaces) hides cleanly, with the "Q" mark hidden along with the question
• The question and any accent text stay readable on a light background
• Re-exported in src/templates/quote/index.ts and registered in the Quote block of src/templates/registry.ts
• Meets the shared template checklist in Add new card-style OG image templates #5

One template per contributor at a time, so more people get a chance.

Want to work on this? Comment below and I'll assign it to you. Please take one issue at a time, branch off dev, and open your PR against dev with Closes #285 in the description.