Refactor Realm and Faction Transforms to Use Shared Utilities

Summary

Realm and Faction share ~90% identical transform code (scene image extraction, description rendering, layout meta tags, content building, createComponentRenderable structure). Refactor both to use the shared utilities from WORK-076 and WORK-077, align their section structure to the standard 3-section pattern, and fix Faction's missing mediaSlots config.

Acceptance Criteria

• Realm transform uses shared buildLayoutMetas() from WORK-076
• Faction transform uses shared buildLayoutMetas() from WORK-076
• Both transforms use shared extractMediaImage() from WORK-077 (replacing ~15-line inline unwrap loops)
• Shared storytelling helpers extracted for any remaining duplicated patterns between Realm and Faction
• Faction config declares mediaSlots: { scene: 'cover' } and corresponding sections entry for scene: 'media'
• Both runes follow standard 3-section structure (meta, content with preamble, media)
• Realm config sections aligned to standard pattern (preamble inside content)
• All existing tests pass (update snapshots if structure changes)

Approach

1. Apply shared utilities from WORK-076 and WORK-077 to both transforms
2. Extract any remaining duplicated storytelling-specific logic into package helpers
3. Fix Faction's missing mediaSlots and sections config
4. Align section structure to standard pattern
5. Update test snapshots

References

• Rune Output Standards (Standard 2 — Preamble Groups with Content)
• Rune Output Standards (Standard 3 — Config Must Match Schema Capabilities)
• Rune Output Standards (Standard 4 — Avoid Duplicated Transform Logic)
• Extract Shared Layout Meta Tag Utility (shared layout meta utility)
• Extract Shared Media Image Unwrap Utility (shared media unwrap utility)