Core types, configuration, and error handling for the CRW web scraper.

This crate provides the foundational building blocks shared across all CRW crates:

• [config] — Layered TOML configuration with environment variable overrides
• [error] — Unified error types ([CrwError]) and result alias ([CrwResult])
• [types] — Shared data structures (ScrapeData, FetchResult, OutputFormat, etc.)
• [url_safety] — SSRF protection (blocks private IPs, cloud metadata, non-HTTP schemes)

Example

use crw_core::{AppConfig, CrwError, CrwResult};

let config = AppConfig::load().unwrap();
assert!(config.server.port > 0);