compat: Value & Amount constructs public for Redux

[matthewjablack]

Problem

The Value and Amount classes had protected/private members that prevented them from working with Redux Toolkit's Immer-based state management:

• protected _picoSats: bigint - Immer proxies couldn't access this property
• protected constructor() - Immer couldn't create new instances during state updates
• TypeScript errors: Property '_picoSats' is missing in type 'WritableDraft<Value>'

Solution

Made the necessary properties and constructors public to enable Immer proxy compatibility:

• protected _picoSats → public _picoSats
• protected constructor() → public constructor() (Value)
• private constructor() → public constructor() (Amount)

Impact

• No breaking changes - all existing APIs work exactly the same
• Enables Redux usage - can now use Value/Amount objects directly in Redux state
• Maintains encapsulation - _ prefix still signals internal use
• All tests pass - 76/76 tests passing with 97.56% coverage

Usage

// Before: Had to use workarounds in Redux
const state = current(draftState); // Required for Value objects

// After: Can use directly in Redux
state.loan.initialBitcoinCollateral = Value.fromBitcoin(2.5); // Works!

The factory methods (fromBitcoin, fromSats, etc.) remain the recommended way to create instances, but direct construction is now possible for framework compatibility.