summary_embeddings.json: 838 chunks from 94 stories, seeds (11, 12, 13)

   k  sized>=5  median dom  recurring  coverage  tight rec  tight cov
----------------------------------------------------------------------
  25        25        0.14         23      97%         11       40%
  40        36        0.17         32      95%         14       36%
  60        51        0.22         41      87%         18       26%
 100        70        0.28         50      73%         20       19%

recurring = size>=5, stories>=4, dominant share<=40%; tight = coherence at or above this file's median cluster. Judge at k>=60. Wrote summary_embeddings.measure.json
exit 0