fix(oracle): on a parse failure, retry with the reliable baseline prompt

fix(oracle): retry when fewer than three films come back

fix(prompt): strip year from title, harden JSON-only instruction

fix(backend): first pass respects refined env flag; add A/B override

feat: avoid repeating films across a session

feat(backend): resilience — timeouts, bounded retry, clean errors

feat(backend): sanitize and re-encode all input before the model

feat(backend): retry once when an interpretation reads flat

feat(backend): make the typed fragment a primary signal

feat(backend): add pluggable LLM oracle for image and fragment input