Provide credential-free stores for local development #131

Description

Make KV, configuration and secret-store interfaces usable locally without cloud credentials or platform emulators.

The Axum runner wires declared stores into per-request registries: persistent redb KV, local JSON config snapshots and environment-backed secrets. These providers implement the portable store interfaces and satisfy the local-development requirement.

Steps to reproduce

1. Inspect Axum local KV/config/secret provider implementations.
2. Inspect development runner registry construction and request-store attachment.

Expected behavior

An application can use its portable KV/config/secret APIs during native local development.

Impact

The requested credential-free workflow already exists; cloud resource provisioning and production providers remain separate work.

Proposed fix

Close as completed using the existing local providers rather than requiring mocks with identical class names.

Done when

• A local KV provider works without a cloud service.
• Configuration values load from local data.
• Secrets resolve from local environment variables.
• The development runner attaches all three interfaces through declared store registries.

Related

• Parent: Complete CLI and local developer workflows #124.
• Local manifest/provision automation: Implement local provisioning across all adapters #288.
• Local persistent KV implementation
• Local config provider
• Environment secret provider
• Local registry wiring

The requested implementation is present on the audited main revision. This audit inspected source and existing coverage; it did not rerun the tests.