Add Vin (identifiers)

[vhrcgcom]

Description

Implement Vin as a ValueObject in the identifiers module.

Spec: Vehicle Identification Number, 17 chars, checksum validated

Implementation checklist

• Create src/identifiers/vin.rs
• Implement ValueObject trait
• Add #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
• Export from src/identifiers/mod.rs and prelude
• Unit tests: valid input · empty input · invalid format · normalisation
• Doc comment with # Example block
• Update status in ROADMAP.md from ⬜ to ✅

Implementation detail

Input / Output

	Type	Alias
Input	String	VinInput
Output	String	VinOutput

Normalization

Trim, convert to uppercase.

Validation

• Exactly 17 characters after normalising.
• Only ASCII letters and digits; the letters I, O, and Q are forbidden (they are excluded from the VIN alphabet to avoid confusion with 1, 0, and 0).
• Check digit (position 9, 0-indexed) must be valid: each character has a transliteration value and a positional weight; compute weighted sum mod 11 and compare against the stored check digit (0–9 or X for 10).

Extra methods

• wmi() -> &str — World Manufacturer Identifier, first 3 characters.
• vds() -> &str — Vehicle Descriptor Section, characters 4–9.
• vis() -> &str — Vehicle Identifier Section, last 8 characters (includes model year and serial number).
• model_year() -> char — character at position 10 (index 9), encodes the model year.

References

• ROADMAP.md
• CONTRIBUTING.md