Add advanced generics for functions and methods #90

Extend named-type applications with generic functions and methods, constraints, defaults, contextual inference, and monomorphization.

Delivered baseline

• PR Add generic named type instances #97 delivered explicit generic named-type applications and deterministic module-qualified instance identity.
• Generic structs, enums, interfaces, and transparent aliases are supported.

Remaining scope

• Generic functions and methods.
• Constraints and defaults.
• Contextual generic argument inference.
• Function/method monomorphization.

Preserve exact explicit named-type arguments as baseline and keep instance identity module-qualified and deterministic.