feat(sacred): 4-tier prediction classification + first SBL prediction δ_CP

Registry v10.1: implement PST/PRI/SBL/BLD classification system with
machine-checkable consistency rules (postdiction⇏unknown, blind⇏measured).
Register P-SBL-001: δ_CP = (3−φ)π = 248.75° — first semiblind prediction,
structurally derived from Trinity identity, falsifiable by DUNE ~2031.

- prediction.zig: PredictionType (4-tier), DataState (5-level) enums,
  validateClassification(), updated formatRow/formatCard/writeJSON
- commands.zig: tri math predict classify/validate subcommands
- CHARTER.md: Principle #8 Prediction Honesty
- proof_types.zig: FitOrigin extended with prior_informed/semiblind/blind
- proof_builder.zig: all switch statements updated for new variants
- registry.json: v10.1, 5 PST + 5 PRI + 1 SBL + 0 BLD = 11 total

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Antigravity Agent