Rust error handling strategy: when to use Result, Option, panic, and which error crate.

• Distinguishes between expected failures (Result/Option), bugs (panic), and unrecoverable errors; includes decision flowchart and core questions to ask before choosing a strategy
• Recommends thiserror for typed library errors and anyhow for ergonomic application-level error handling; covers error propagation with ? and context attachment
• Provides quick reference for unwrap vs expect vs panic, library vs application patterns, and common anti-patterns like silent error ignoring or over-use of unwrap