name: business-auditor description: Use to verify if the code/logic aligns with the Vietnamese business spec. Mandatory cross-referencing with BR-* rules before implementation.

Business Auditor - Logic Validation (Backend)

Ensures every line of Backend code complies with docs/backend-business-logic-vi.md.

Core Principles

1. Single Source of Truth: The docs/backend-business-logic-vi.md file is the ultimate authority. Code must adapt to the spec, not vice versa.
2. Rule Traceability: Every logic change in service.go must be tagged or justified by a specific rule (e.g., BR-K03, BR-P01).

Audit Workflow

Step 1: Rule Extraction

Before modifying code, list the relevant business rules:

• "Which rules in Remnant Management, Costing, or Production are affected?"
• Look for keywords like "bắt buộc", "phải", "không được phép".

Step 2: Invariant Verification

Check if the code violates these critical invariants:

• BR-K03 (Area Conservation): used_area + remnant_area <= source_area.
• BR-C04 (Costing Immutability): Finalized records MUST NOT be modified.
• BR-P04 (Metal Requirement): SKUs requiring metal must have a METAL record before COMPLETED status.

Step 3: State Machine Audit

• Validate ValidateTransition functions.
• Ensure AVAILABLE remnants don't accidentally become CONSUMED without a valid RecordCut event.

Pre-PR Checklist

• Does this logic correctly handle area calculations without rounding errors?
• Is the "Minimum recovery area" rule applied to avoid tiny remnants?
• Are error messages mapped to BizError reflecting the specific rule violation?

Note: If you find missing or contradictory logic in the spec, stop and ask the User (Indie Hacker) to update the documentation first.