Extends spectral_codebook_v3 from 2 to 4 resolution profiles:
- 1024x1024 (existing, 100b+100w refs)
- 1536x2816 (existing, 88 watermarked refs)
- 1344x768 (new, 154b+364w refs, top carrier coherence 0.946)
- 864x1184 (new, 268b+295w refs, top carrier coherence 0.979)
Key findings at new resolutions:
- 1344x768 carriers sit on the vertical axis (fy=0, fx=3..10)
- 864x1184 carriers are at mid-frequency diagonals (13,-16), (23,-24)
- Both show distinct carrier structures vs existing profiles,
confirming resolution-dependent embedding
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>