Function decodeJwt

decodeJwt<TPayload extends JwtPayload = JwtPayload>(
token: string,
): JwtToken<TPayload>
Decode a compact-serialisation JWT string into its constituent parts: header, payload, and raw signature.

This function does NOT verify the token's signature. Signature verification requires access to the signing key or a JWKS endpoint and is the responsibility of the consumer's backend or auth library.
Type Parameters
- TPayload extends JwtPayload = JwtPayload
Parameters
- token: string
  A JWT in compact serialisation (header.payload.signature).
Returns JwtToken<TPayload>
A JwtToken with decoded header and payload.
Throws
If the token structure is malformed or the JSON is invalid.
Example
```
import { decodeJwt } from '@theredhead/lucid-foundation';

const jwt = decodeJwt(rawTokenString);
console.log(jwt.payload.sub);  // "user-123"
console.log(jwt.payload.exp);  // 1742601600
```
- Defined in packages/foundation/src/lib/jwt/jwt.parser.ts:72