ci(security): add prompt-injection scanner for docs and repo text

[ibloud]

🎯 Purpose of this PR

This PR introduces the foundational technical architecture blueprints and narrative design guidelines into the /docs directory. It establishes the onboarding framework for incoming community systems engineers, technical artists, and variant designers.

🛠️ Changes Implemented

• Added docs/ARCHITECTURE_OVERVIEW.md: Outlines the core dynamic move calculation loop pipeline, provides an extensible component blueprint for variant design (GhostPiece script example), and defines our target atproto/Improbable integration strategy.
• Added docs/PUBLIC_DOMAIN_DESIGN.md: Documents our legally compliant, copyright-free integration of classical philosophy (Seneca/Epicurus), mythological archetypes (Thanatos' inverted torch), and 19th-century literature (Poe/Rossetti) to anchor the mechanics of the "Restraint Fantasy" and grief processing.

📋 Architectural Verification

• Verified alignment with the core 14x14 cross topology rulebook layout defined in README.md.
• Confirmed that code-contribution boundaries explicitly protect the Daddy's Little Mortis commercial IP under the repository's CC BY-NC-SA 4.0 license.

📬 Next Steps for Reviewers

Please verify that the proposed pipeline hook points inside the documentation match our intended Unity/Unreal component architecture before this is merged into the default branch.