Archived several outdated reports (`Ping-Service_Impl_01-2026.md`, `Frontend_Integration_Status.md`, etc.) and added archival notes and references to updated documents. Introduced a centralized reference structure for tech stack documentation, consolidating files under `01_Architecture/Reference/Tech_Stack`. Added new resources (`Gradle_Kotlin_DSL_Primer`, `Kotlin_2-3-0_ReleaseNotes`) for improved project organization and clarity.
Introduced detailed documentation for the API Gateway, including its configuration and responsibilities in the system (e.g., routing, security, and cross-cutting concerns). Added a README for the core model directory to define its structure and workflow. Created a new backend README to describe its components and their documentation structure. Simplified and clarified legacy specifications for archiving purposes.
Implemented a standardized folder structure for domain documentation to improve clarity and maintainability. Migrated existing files to the new structure, updated links in related documentation, and added README files for navigation and guidance.
