feat(types): add @oasty/types with OpenAPI 3.0-3.2 type definitions

[dinwwwh]

Adds the @oasty/types package: fully documented TypeScript types for the OpenAPI Specification, authored against 3.0.4, 3.1.2, and 3.2.0 — one module per minor version, exported as @oasty/types/v3.0–v3.2 plus root namespaces and cross-version unions. Each version re-exports what is structurally unchanged from the previous one and redefines only what changed, so the spec's evolution (JSON Schema 2020-12 in 3.1, $self/QUERY/querystring/streaming in 3.2) is visible in the type layer itself.

Design

• Type names mirror the spec's section names, and every field carries its spec description as JSDoc with @see links, @default, and @deprecated where the spec says so.
• Conditional requiredness is encoded where the spec tables define it: security schemes and OAuth flows are discriminated unions, 1XX–5XX response keys and /-prefixed paths are template-literal index signatures, and each version's openapi field is version-typed for narrowing.
• SchemaObject<T = unknown> types the data-carrying fields (enum, default, example, and const/examples in 3.1+); the default keeps plain SchemaObject unchanged.
• Semantic-only rules (mutual exclusions, at-least-one-of containers, per-location applicability) are documented rather than force-encoded, keeping error messages usable.

Verification

• Reviewed field-by-field against the official spec documents; all confirmed discrepancies fixed.
• All 83 official valid documents compile: the OAI example set (3.0/3.1/3.2) and both tests/schema/pass suites from the spec repo, committed as a regression corpus under packages/types/tests that root tsc re-checks; the popular Train Travel API also compiles clean.
• Of the official tests/schema/fail documents, the type-expressible ones are rejected for the right reasons — including 3.2-only values (style: "cookie") failing in the 3.1 module.
• Version boundaries are pinned by @ts-expect-error tests (nullable vs type arrays, boolean vs numeric exclusive bounds, no webhooks in 3.0, no QUERY before 3.2).

Tooling

• Builds with unbuild using orpc-style dev/publish exports (src/*.ts in dev, dist/*.d.mts + .mjs when published); declarations keep all JSDoc.
• sync:sponsors now lint-fixes exactly the files that changed, discovered via git rather than hardcoded paths, so future directories are covered automatically.
• tsconfig.lib.json drops the DOM libs; type:check, lint:check, test, and the package build are all green.