feat(core): sync models.dev reasoning options

[rekram1-node]

Summary

• parse provider-specific reasoning_options from models.dev using typed known variants plus an open fallback for future option types and fields
• expose a discriminated toggle | effort | budget_tokens union through legacy provider and V2 model capabilities
• normalize raw options at catalog boundaries: retain open effort strings, remove nullable no-reasoning markers, and ignore unknown option types without failing refreshes
• preserve typed reasoning options through provider configuration overlays and regenerate SDK types

Compatibility

• raw models.dev decoding accepts and preserves unknown option types and additional fields
• resolved HTTP/SDK models expose the currently supported typed union
• new effort values remain valid because effort values are open strings

Testing

• bun test test/models.test.ts test/plugin/models-dev.test.ts in packages/core
• bun test test/provider/provider.test.ts in packages/opencode
• bun typecheck in packages/core
• bun typecheck in packages/opencode
• bun typecheck in packages/sdk/js
• git diff --check