Logging: Implement structured logging and configurable log levels

[0xDevNinja]

Summary

To elevate the project to an industry level, we need comprehensive logging across modules. Add structured logging to capture key events, errors, and metrics.

Tasks

• Add log and env_logger dependencies to Cargo.toml with appropriate features.
• Create a new module src/logging/mod.rs that exposes a function init_logging() which initializes the logger using env_logger.
• Configure the logger to read log level from the RUST_LOG environment variable with a sensible default (e.g. info).
• Use log::info!, log::debug!, log::warn!, and log::error! macros in critical modules (solver, matching, routing, pricing, adapters, bridge, strategies) to record lifecycle events, decisions, and errors.
• Update the CLI binary and daemon service to call logging::init_logging() at startup.
• Add documentation to the README explaining how to set RUST_LOG for different environments and how to interpret logs.
• Provide unit tests (or integration tests) that verify logging initialization does not panic and respects log level configuration.

Acceptance Criteria

• When running the solver or daemon, logs are printed to stdout with timestamps and module names.
• Changing RUST_LOG=debug in the environment enables debug-level logs.
• The logger must not impede performance or crash the application.
• The README is updated with logging instructions.