feat: Add Claude Sonnet 4.5 support

[krzemienski]

Summary

Adds support for the newly released Claude Sonnet 4.5 model (claude-sonnet-4-5-20250929).

Closes #43

Changes

• ✅ Add SONNET_4_5 model ID to CLAUDE_MODEL_IDS
• ✅ Add display name ("Claude Sonnet 4.5") and short name ("claude-sonnet-4.5") mappings
• ✅ Add SONNET_4_5 to ALLOWED_MODELS for agent usage
• ✅ Add pricing configuration ($3 input, $15 output per 1M tokens, matching Sonnet 4)
• ✅ Add "sonnet-4.5" CLI shorthand mapping for --set-model command

Implementation Pattern

Follows the same implementation pattern as Opus 4.1 (commit 98556ae):

• packages/core/src/models.ts - Model ID, display name, and short name
• packages/types/src/agent.ts - Added to ALLOWED_MODELS array
• packages/core/src/pricing.ts - Pricing configuration
• apps/tui/src/main.ts - CLI shorthand mapping

Testing

• ✅ All quality checks passed: bun run lint && bun run typecheck && bun run format
• ✅ No syntax errors or type errors
• ✅ Pricing matches official Anthropic pricing

Model Details

• Model ID: claude-sonnet-4-5-20250929
• Display Name: Claude Sonnet 4.5
• Short Name: claude-sonnet-4.5
• CLI Usage: ccflare --set-model sonnet-4.5
• Pricing: Input $3/M tokens, Output $15/M tokens (same as Sonnet 4)

[krzemienski]

is this the reason why ccflare usage is different than the one I see in claude.

Probably - also now with haiku being introduced and if you are using the agent override model proxy it could be doing it

[cantalupo555]

Isso funciona melhor para mim https://github.com/tombii/better-ccflare

O uso é obtido diretamente da Anthropic.

@bitcoin4cashqc Thanks