feat(suite): expose provider sampling options

[vsolano9]

Closes #17.

Suites and cases can now declare temperature and maxTokens. Case values override suite defaults; absent temperature deliberately resolves to 0 for reproducible regression runs, while an absent token cap remains omitted.

The loader rejects negative/non-finite temperatures and non-positive/non-integer token caps at both levels. README and both bundled suites demonstrate the public fields, including case overrides.

Validation:

• RED: 7 behavioral failures plus expected public-type errors
• 76/76 tests; 22 focused loader/runner tests repeated 20 times
• lint, typecheck, and production build
• both bundled suites passed unchanged: support 94.2%, summarizer 92.0%
• full lint/typecheck/build/test/example gate on exact Node 20.20.2 and 22.23.2
• clean installed-tarball public API/provider-request smoke
• production dependency audit: 0 findings
• git diff --check

All validation is offline and mock-first; no provider key or network model call is used.

[vsolano9]

Postflight clarification for the red quality-gate context:

• the comparison itself completed successfully: base 94.2% -> head 94.2% (0.0pp)
• it explicitly reported No regressions beyond tolerance.
• the job then exited 2 only when the fork-scoped token received HTTP 403 creating the optional PR comment

The independent Node 20/22 CI run passed typecheck, lint, build, all 76 tests, and the example smoke on this exact head.

Runs: quality comparison · Node 20/22 CI