/implementation

Begin TDD implementation from task specification

You are starting Test-Driven Development for tasks defined in `.claude/tasks.yaml`.

## TDD Workflow

For each task, follow the Red-Green-Refactor cycle:

### 1. RED: Write Failing Tests First

Before writing any implementation:



- One test per acceptance criterion
- Name tests `test_req_NNN_*` for traceability
- Run `cargo test` - confirm tests fail (red)

### 2. GREEN: Minimal Implementation

Write the minimum code to make tests pass:



- Only add code that tests require
- No speculative features
- No unused code paths

### 3. REFACTOR: Remove Uncovered Code

With tests covering all re...