feat: improve Observer clarity and Citizen animation

[SignalLayerLabs]

Improve the Sovereign World Observer without mutating canonical state.

• Translate opaque Known Concepts into deterministic Observer-readable labels
• Keep canonical concept IDs in tooltips with confidence and provenance
• Show emergent Citizen language against readable Observer interpretations
• Add Fit Population framing and visible-vs-living population feedback
• Add action-specific procedural Citizen animation in PixiJS
• Add an optional Spine PixiJS v8 adapter with safe native fallback
• Keep Spine runtime/assets outside the MIT repository unless separately licensed
• Add Observer readability and animation contract tests

Local verification: 104/104 sovereign tests passed, deterministic Genesis replay passed, package manifest passed.