Add formal tool attribution block to review output

[melek]

Problem

The review output (review.md) mentions Stepwise in the methodology section and PRISMA-trAIce T1 item, but lacks a formal, structured attribution block that:

1. Names the tool and version
2. Links to the repository
3. States the generation method (inference-driven, autonomous phases)
4. States the scope of human oversight

When reviews are copied into downstream repos (e.g., as citable reference material in a project's docs/research/ directory), the attribution should travel with the document without requiring someone to read the methodology section.

Proposed Fix

Add a blockquote attribution block immediately after the title in review.md, before the Abstract:

> Generated by inference with [Stepwise](https://github.com/melek/stepwise) v{version} (autonomous systematic literature review, Claude Code plugin). Kitchenham SLR protocol with Wohlin snowballing, PRISMA 2020 compliance. Human oversight limited to protocol approval (Phase 0). Full reproducibility workspace: see protocol.md in this directory.

Implementation

1. Synthesis runbook (runbooks/synthesize.md): Add the attribution block as a required element in the review template, populated with the plugin version from plugin.json and the GitHub repo URL.
2. Review templates (templates/review-template-prisma.md, review-template-kitchenham.md, review-template-narrative.md): Add a [TOOL_ATTRIBUTION] placeholder after the title.
3. SKILL.md orchestrator: Populate the attribution block with the actual version and repo URL when writing review.md.

The attribution should be part of the generated output, not something the user has to add manually.

Context

Discovered when copying a review into the UIDI repo as citable reference material. The attribution was added manually. This should be automatic for all future reviews.