feat(atlas): add the Aion support agent

[davidb73-hub]

What changed

• Added Atlas as a repository-scoped Aion custom agent.
• Added a project skill with a machine-readable library of 76 documentation sources and 32 source-code areas.
• Added deterministic topic routing and a freshness check covering all 21 tracked authoring documents.
• Added privacy-safe collective-learning rules: reusable lessons must be verified, anonymized, explicitly approved, and reviewed through Git.

Why

Aion users need fast, evidence-backed guidance from the current documentation and implementation without copying the repository into a second knowledge base that will drift.

User impact

Inside an Aion checkout, users can invoke the $aion-atlas skill or select the aion_atlas custom agent. Atlas routes each question to the smallest authoritative set of current docs, source files, entry points, and tests.

Interactions are not uploaded automatically. Only distilled, generalizable, non-sensitive learnings may be proposed for the shared repository, and publication requires explicit user approval plus normal pull-request review.

Validation

• Official Codex skill validator: passed
• Library integrity: 76 sources, 32 code areas, 21/21 authoring files, 91 topics
• Beginner document routing: passed
• Engine source-code routing: passed
• Python syntax and TOML parsing: passed
• Codex project skill discovery: passed