feat(protocol): add enforceable boot sequence support

[mmilanez]

Problem

The Lead Protocol defines a boot sequence, but today compliance is mostly textual. Agents can skip the required files and still proceed, which weakens continuity across sessions.

Proposed change

Design and implement a lightweight boot mechanism, such as a boot helper script and optional receipt, that makes the canonical read order easier to execute and easier to audit.

Acceptance criteria

• A documented boot command exists for agents that can run shell commands.
• The command reads the protocol files in canonical order.
• The mechanism records enough evidence to help detect skipped boot steps.
• The design remains vendor-neutral and does not depend on one agent product.