chore(bench): add vitest benchmarks for runtime and type-checking performance

[Copilot]

Establishes baseline benchmarks for runtime builder performance and TypeScript type-inference cost, enabling data-driven type optimization.

bench/runtime.bench.ts

Measures JS execution speed across the full builder API surface:

• Operation builder – 8 cases from flat string fields to 4-level deep nesting, variables+args, inline fragments, directives, mutations
• Fragment builder – simple, with variables, with directives
• Partial builder – create package, spread into query
• Gazania facade – public gazania singleton for each builder type

bench/type.bench.ts

Measures getSemanticDiagnostics() time via the TypeScript compiler API across 8 scenarios of increasing selection complexity:

simple scalar → flat multi-field → nested 1-level → nested 2-levels
  → union inline fragments → partial spread → fragment → complex mixed

Each iteration creates a fresh ts.createProgram + compiler host to avoid cache pollution. Uses { iterations: 3, warmupIterations: 1 } since each TypeScript compilation costs ~500ms. Each case asserts zero type errors so broken fixtures surface immediately.

Compiler setup: types: ['vitest/importMeta'] + typeRoots pointing to project node_modules silences the import.meta.vitest guards present in source files. The virtual file lives at bench/_virtual_type_bench_.ts so relative imports (../src/index, ../test/types/schema) resolve against the real project layout without absolute paths.

vitest.config.ts

Added benchmark: { include: ['bench/**/*.bench.ts'] }.

Run with:

vitest bench --run

[cloudflare-workers-and-pages]

Deploying gazania with    Cloudflare Pages

Latest commit:	e092444
Status:	✅  Deploy successful!
Preview URL:	https://c1539c12.gazania.pages.dev
Branch Preview URL:	https://copilot-add-benchmark-for-ru.gazania.pages.dev

View logs