Honor RUST_LOG for development output #127

Description

Respect the RUST_LOG environment variable for development-server logging, with documented precedence against EdgeZero logging configuration.

The CLI logger fixes its maximum level to Info and drops Debug/Trace. Axum initializes SimpleLogger from EDGEZERO__LOGGING__LEVEL; neither path reads RUST_LOG.

Steps to reproduce

1. Inspect CLI logger filtering and initialization.
2. Inspect the native development runner's logging-level resolution.

Expected behavior

A developer can select development log verbosity through RUST_LOG without changing code.

Impact

A familiar development logging control currently has no effect, obscuring debug output.

Proposed fix

Implement an explicit filter/precedence contract for runtime development logs and preserve predictable command-result output.

Done when

• Supported RUST_LOG syntax affects development logging.
• Precedence with EDGEZERO__LOGGING__LEVEL/manifest defaults is documented and tested.
• Invalid filters have clear fallback/error behavior.
• Debug/trace runtime events can be observed without changing application source.

Related

• Parent: Complete CLI and local developer workflows #124.
• Cross-runtime logging: Provide consistent structured logs across adapters #119.
• CLI fixed-level logger
• Axum logging initialization