Replace custom logging with tracing crate and RUST_LOG env var

- Remove custom logging module and init_logging function
- Update main.rs to use tracing_subscriber with EnvFilter
- Remove log_level from global config structure
- Update documentation and tests to use RUST_LOG
- Format long lines in config.rs and test files for better readability

README.md

@@ -115,9 +115,26 @@ Access with a Gemini client like Lagrange at `gemini://yourdomain.com/`.
 ## Options
 
 - `--config` (`-C`): Path to config file (default `/etc/pollux/config.toml`)
-- `--no-tls`: Disable TLS for testing (uses raw TCP connections)
 - `--test-processing-delay` (debug builds only): Add delay before processing requests (seconds) - for testing rate limiting
 
+## Logging
+
+Pollux uses the `tracing` crate for structured logging. Configure log levels with the `RUST_LOG` environment variable:
+
+```bash
+# Basic usage
+export RUST_LOG=info
+./pollux
+
+# Module-specific levels
+export RUST_LOG=pollux=debug,sqlx=info
+
+# Maximum verbosity
+export RUST_LOG=trace
+```
+
+Available levels: `error`, `warn`, `info`, `debug`, `trace`
+
 ## Security
 
 Pollux is designed with security as a priority: