# Utility
The general-purpose helpers the platform's services share: small, single-purpose methods with no dependencies beyond Foundation and no ties to any web framework.

## Overview
| Role | Types |
| --- | --- |
| Validation | `NormalizeEmail`, which reduces a submitted email address to its canonical form |

## Design rules
- **Dependency-free.** A helper belongs here only while it needs nothing beyond Foundation; one that grows a framework dependency belongs in the package owning that framework's concerns (e.g. `Infrastructure` for Hummingbird).
- **Method structs.** Helpers hold their lifetime-fixed configuration in `init` and take only per-call inputs in `callAsFunction`.

## Layout
Sources are split by visibility, then by kind, one type per file:
```
Sources/
└── Public/
    └── Methods/           NormalizeEmail
Tests/
├── Cases/                 the test suites, mirroring the Sources/ layout
└── Utils/                 the suite Tag constants
```

## Testing
Every suite carries a tag for the kind of API it exercises — `.method`, declared in `Tests/Utils/Extensions/Tag+Constants.swift` — so test plans and summaries can slice a run by kind. A new suite adopts the tag matching its subject, or adds one when none fits.

## Requirements
- Swift 6.3 toolchain (`swift-tools-version:6.3`).
- macOS 15, matching the sibling packages (the services deploy to Linux containers; the packages carry no UI platforms).
- No package dependencies — Foundation only.