feat(module): INBOX drop-folder assisted classification

[mmilanez]

Problem

Some projects need a simple intake surface where humans can drop unclassified notes, files, or requests and ask an agent to classify them into the right protocol or project destination.

Proposed change

Design an optional INBOX module for drop-folder workflows with clear classification rules and auditability.

Acceptance criteria

• The module is opt-in and has no overhead for projects that do not use it.
• The workflow defines what belongs in the inbox and how items are moved out.
• Classification actions are traceable without storing private content in shared protocol files unnecessarily.