result.score was required by zod; the LLM (gemini-3.5-flash-lite via 9router)
occasionally omits it for media batches, hard-failing the whole batch parse
('Zod validation failed: expected number, received undefined' at
results[0].score). Callers already null-coalesce (result.score ?? 0) and the
parser clampScore()s it, so requiring it only caused parse failures.
Adds regression tests: media-batch without score parses (score->0), and
score-present responses still parse with the value.
asepharyana
e6aa9af283