Release 4.8.6

Prompt Diversity Pipeline

The validator's prompt generation pipeline has been rebuilt to break a
single-register monoculture. Previously the composer LLM defaulted to polished
cinematography for every prompt regardless of source — "a close up" opened 36% of
video prompts, "as if" appeared in 72%, and every prompt shared the same literary
voice. The new pipeline samples visual register, shot structure, length, and
style outside the LLM and injects them as authoritative constraints the model
must render.

Architecture

• Register sampling — 12 visual registers (phone_casual, cctv_surveillance,
  drone_aerial, cinema_polished, etc.) with weighted probabilities. Each prompt
  gets a committed spec dictating register, camera motion, length band, event
  count, and whether literary phrasing is banned ("plain" registers).

• Scene remixing — 25% of scenes are semi-synthetic variants where contextual
  fields (time of day, weather, setting, mood) are resampled while preserving the
  grounded subject. Breaks scraper distributional bias without artificial scene
  generation.

• QC gate — every composed prompt is validated against its committed spec.
  Rejects LLM meta-chatter, bullet lists, length-band violations, and banned
  phrases in plain registers. One retry with the rejection reason appended; a
  second failure drops the sample.

• Near-duplicate guard — 5-gram Jaccard similarity checked against the last
  200 same-modality prompts at write time. Paraphrase-level repeats are rejected.

• Diversity report — scripts/prompt_diversity_report.py quantifies opener
  trigram share, phrase tells, near-duplicate rates, and register distribution.
  --check mode exits non-zero on threshold breaches — suitable for CI canaries.

Measured impact

Metric	Old	New	Change
Video opener max share	35.9% ("a close up")	20.6% ("the phone camera")	−15.3 pp
Image opener max share	32.4% ("a close up")	11.2% ("a close up")	−21.2 pp
"as if" per video prompt	0.724	0.206	−0.52 pp
"stillness" per video prompt	0.407	0.150	−0.26 pp
Registers in use	1 (cinematic)	12 distinct	—
Cinema_polished share	100%	13%	—

All 12 registers are in active rotation. phone_casual leads at 21.5%;
cinema_polished — the old pipeline's de-facto only register — accounts for
only 13% of new prompts.

C2PA Model Audit

Two models removed from the validator's accepted set after live C2PA testing:

• bytedance/seedance-1-5-pro — produces no C2PA/JUMBF data in output.
  Miners generating from this model were getting verified as "no upload" and
  penalized. Only Seedance 2.0 variants are validator-eligible.

• Runway gen4.5 — C2PA manifest present but claimSignature.mismatch.
  Runway's signing infrastructure bug. Re-enable when Runway fixes their
  signing.

Seedance 2.0 pricing corrected: seedance-2-0-fast $0.05 → $0.12,
seedance-2-0 $0.12 → $0.15 (previous figures were inaccurate).

Seedance on Runway

seedance2 and seedance2_fast are now available through the Runway service
in addition to OpenRouter. Both produce C2PA-signed content (Byteplus Pte.
Ltd. signature) and are validator-eligible. Supports 4–15 second durations,
up to 1080p, and square (1:1) through 21:9 aspect ratios.

Modality Reward Weights

Generator reward weights adjusted:

Modality	Before	After
Video	0.94	0.88
Image	0.06	0.12

Doubles the image contribution to miner rewards while keeping video dominant.