Function init 

pub fn init() -> Result<()>

Initialize observability stack

Sets up:

• Structured logging with JSON formatting (production) or pretty formatting (dev)
• Environment-based log level filtering
• Request ID correlation

Errors

Returns an error if:

• The tracing subscriber global default cannot be set (already initialized)
• Environment filter parsing fails for invalid RUST_LOG values

Example

use acton_htmx::observability;

observability::init()?;
tracing::info!("Application started");