Add CLAUDE.md (AI agent guide)

[carochacs]

This plugin has no CLAUDE.md — an AI-agent-facing guide covering plugin-spec compliance (folder/id match, context['load_sibling'] for cross-file imports, context['log'] not print(), idempotent screen.js, route namespacing under /api/plugins/<id>/...) and this plugin's own conventions (versioning policy, notable gotchas).

Reference: got-feedBack/feedBack-plugin-spec (spec/plugin-spec-v1.md, spec/best-practices.md) for what a compliant plugin should follow; feedBack-plugin-editor and feedBack-plugin-feedpaker for worked examples of what a plugin's own CLAUDE.md looks like in practice.

Filed while auditing plugin docs across the org — same gap found on ~30 other feedBack-plugin-* repos.

[carochacs]

Added in get-flashbacks#3: CLAUDE.md covering plugin-spec compliance (idempotent script guard, seek-through-Host-funnel, no direct dynamic_difficulty coupling) and versioning policy. PR: get-flashbacks#3