Batch Train UI

Flows, auto-batching (≤15.9k tokens), auto filenames, OpenAI gpt-4o via local runner. Server auto-estimates tokens/record and batches.
📊 Gap Analysis (Flow 1 Only): Server scans 500+ theme vocabulary vs quotes.json. Returns themes with <2 quotes (gaps). Includes spelling correction and rare author selection. This flow is specifically designed to fill search gaps - themes that users search for but have no results. Other flows (2-5) are for targeted content generation and do NOT use gap analysis.