v2.12.3 — figma-rigor hook/framework/cta + character override

Upgrades hook + framework + cta layout templates in carousel_prompt_builder.py with figma-style explicit typographic hierarchy (PRIMARY HEADLINE / SUBTITLE on separate pill / MAIN SUBJECT integrated, with explicit sizing %s and design discipline). Adds optional visual_hint field to FrameworkContent + CtaContent so character-driven decks can override scene policy via content (not global config). Validated with character-driven 3-slide course-invitation deck — framework now reads as designed infographic with per-card eyebrow + body hierarchy, not floating word-chips. Other 6 role layouts not yet upgraded — incremental v2.13 task.