Establish Documentation Architecture Overview

[HusseinAdeiza]

Problem:
There is currently no single high-level architecture or system overview in the documentation (e.g., how components, services, data flows, or domains relate). Readers must infer structure from scattered pages, which slows onboarding and increases the risk of duplication or misunderstanding.

Proposed Solution:

• Add an /architecture/overview.md (or similar) file with a C4-style Context and Container diagram (even a lightweight version).
• Link the new overview from the main README and site navigation/sidebar.
• Store diagram source-of-truth in a diagrams/ folder (preferably as PlantUML or Mermaid text, not just static images).

Acceptance Criteria:

• At least one architecture diagram is committed in text form (not only as a binary image).
• The overview page is discoverable via navigation.
• Existing conceptual pages include cross-links to the overview as appropriate.

Impact:
High – This will accelerate onboarding, clarify system boundaries, and reduce duplicate explanations across the docs.

Priority:
High