Enforce generated OpenAPI types as the source of truth for SDK and CLI APIs

[arawrdn]

PR Description

This change formalizes the generated OpenAPI types as the single source of truth for all OpenSea v2 SDK and CLI endpoint work.

Performance and Reliability Impact

• Prevents duplicated hand-written request/response types from drifting from the OpenSea API contract.
• Reduces runtime mismatch risk by surfacing schema issues during type-checking and build steps.
• Keeps SDK and CLI consumers aligned with the latest generated @opensea/api-types definitions.
• Preserves src/generated.ts as a reproducible artifact generated directly from the OpenAPI spec.
• Improves CI signal quality by ensuring API-path changes are validated against regenerated API types.

Required Development Flow

Before adding or modifying SDK/CLI endpoints:

pnpm --filter @opensea/api-types run update-spec
pnpm --filter @opensea/api-types run build
pnpm --filter sdk run check-types
pnpm --filter cli run build

Engineering Guidance

New endpoints should reuse components["schemas"] or named exports from packages/api-types/src/index.ts instead of introducing parallel local types.

CI enforcement should remain strict around pnpm check-api-paths, ensuring SDK/CLI API-path changes are paired with regenerated packages/api-types updates whenever the OpenAPI spec changes.