fix(runtime): classify repeated adjudicated-revision validation failures (#293)

[akoita]

Closes #293

Summary of Changes

1. Failure-Stage Classification:

   • Introduced ProviderFailureStage and RunFailureStage distinguishing four content-free failure stages:
     • transport-parsing
     • response-schema-validation
     • artifact-schema-validation
     • factual-invariant-rejection
   • Propagated failureStage across ProviderAdapterError, RunError, and AuthorRetryFeedback.
   • Populated specific diagnostic codes in completeCvProposalIssues: "missing_evidence", "unsupported_claim", "factual_invariant_violation".

2. Sanitized Deterministic Coverage:

   • Added packages/application/src/adjudicated-revision-validation.test.ts reproducing the confirmed 10-finding carrier shape (2 accepts, 2 rejects, 6 nuances, 2 accepted effect overrides).
   • Validated classification for each stage without leaking candidate prose, raw text, credentials, or file paths.
   • Validated that a representative valid revised artifact passes production validation to awaiting-approval.

3. Hotspot Lineage:

   • Extracted proposalDiagnostics and invalidAuthorProposalError from packages/application/src/local.ts to packages/application/src/author-output.ts.
   • Reduced local.ts line count from 4,059 to 4,019 lines and lowered its architecture hotspot limit accordingly in scripts/architecture-hotspots.mjs.

4. Quality Gates:

   • pnpm format, pnpm lint, pnpm typecheck, pnpm test (1,275 unit tests + 54 release tests), and pnpm validate pass 100% cleanly.