Remove amount and maxAmount fields

[The-Chest-Library]

Summary

Refactor StackSlot<T> to eliminate state synchronization issues between Content, Amount, and MaxAmount by introducing a single source of truth and explicit mutation methods.

Motivation

The current implementation:

• Uses mutable property setters for Content, Amount, and MaxAmount
• Requires cross-property synchronization
• Risks invariant violations such as Amount not matching actual content
• Contains hidden side effects inside setters
• Allows inconsistent states after public operations

Proposed Change

1. Remove Mutable Setters

Remove public setters and protected fields from:

• Amount
• MaxAmount
  Make them read-only properties.

2. Single Source of Truth

The internal array content must be the only source of truth.

[Chingling152]

The field content now can be resized and it might not be a good idea to remove it.