Use this agent when you encounter unexpected behavior, errors, or bugs in your code that need systematic investigation and resolution. Examples: <example>Context: User is working on an Angular component that's not displaying data correctly. user: 'My receipt table component is showing empty rows even though the API is returning data. The network tab shows the data is coming through but nothing renders.' assistant: 'I'll use the bug-investigator agent to systematically analyze this rendering issue and determine the root cause.' <commentary>Since this is a bug that needs systematic investigation, use the bug-investigator agent to analyze the data flow, component lifecycle, and potential binding issues.</commentary></example> <example>Context: User encounters a build error they can't resolve. user: 'I'm getting a TypeScript compilation error about property not existing on type, but I can see the property is clearly defined in the interface.' assistant: 'Let me use the bug-investigator agent to analyze this TypeScript compilation issue.' <commentary>This is a compilation bug that requires systematic investigation of type definitions, imports, and TypeScript configuration.</commentary></example>