feat(storage): add runner config consumer

[edersonbrilhante]

Description

Adds the provider-neutral runner-config consumer and its AWS SSM implementation. The consumer polls the configured per-runner token path until a one-time JIT or registration configuration is available, applies bounded per-call and overall timeouts, and supports cancellation during polling and backoff.

After reading a configuration it deletes the consumed parameter with bounded retries, classifies retryable provider failures, validates the storage context and environment-derived limits, and exposes safe failure behavior to compute providers. The old environment-based factory remains as a deprecated compatibility alias while callers migrate to createRunnerConfigConsumer.

Test Plan

• Added/updated consumer tests for polling, timeout, cancellation, retry, deletion, and error sanitization.
• git diff --check passed.
• Runtime Yarn tests could not be run locally because the repository's pinned Yarn launcher is unavailable in this environment; CI should provide the full test result.

Related Issues

• Related storage-backend work: feat: add optional DynamoDB runner config storage #5266

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None