Wire CastingEngine into CLI init flow

[bradygaster]

Closes #342

Summary

Integrates the CastingEngine class (from #138) into the CLI squad init flow. Now when users initialize a Squad, the LLM proposes roles and the CastingEngine allocates curated character names and personalities from the universe templates.

Changes

• cast.ts: Add �ugmentWithCastingEngine() to map LLM-proposed universes (e.g., 'The Usual Suspects') to engine universe IDs and replace arbitrary names with curated characters
• coordinator.ts: Update init prompt to guide LLM toward preferred universes (The Usual Suspects, Ocean's Eleven)
• shell/index.ts: Call �ugmentWithCastingEngine() after parsing team proposal
• generateCharter(): Use CastingEngine personalities and backstories when available
• Tests: Add integration test suite to verify augmentation logic

Behavior

• Before: LLM picks arbitrary names (e.g., 'Ripley', 'Dallas', 'Kane') from any universe
• After: If LLM picks a recognized universe, CastingEngine replaces names with curated pool (e.g., Keyser, McManus, Fenster for Usual Suspects)
• Fallback: If universe not recognized, preserves LLM's original names

Testing

• All existing tests pass (45 casting/parser tests)
• New integration tests validate augmentation logic for both universes
• Build successful with strict TypeScript checks

Next Steps

This is the foundational wiring. Future work can expand universe selection scoring (size_fit + shape_fit + resonance_fit) in the LLM prompt.