Intents as signed constraints

An intent is a signed declaration of constraints.

It is not:

• a transaction
• a route
• a promise of execution

Instead, it authorizes execution only if constraints are satisfied.

Key properties:

• the intent is signed once
• execution may involve multiple on-chain steps
• funds move strictly according to the signed intent
• the intent expires automatically after its deadline

This allows execution logic to operate independently while remaining fully user-authorized.