Verify diagrams are in Mermaid.js format for GitHub rendering

[Copilot]

Status

All diagrams in application_documentation/02-architecture/diagrams/ are already in Mermaid.js format. No conversion required.

Files Verified

• c4-model.md: 7 diagrams (C4Context, C4Container, flowchart)
• erd.md: 6 diagrams (erDiagram, stateDiagram-v2)
• flows.md: 20 diagrams (sequenceDiagram, flowchart, stateDiagram-v2)
• README.md: Index file, no diagrams

All code blocks properly use ```mermaid markers and are GitHub-compatible.

Changes

None. This PR documents verification that the requirement is already satisfied.

Original prompt

The repository has diagrams in the "application_documentation/02-architecture/diagrams" directory presented as text blocks. These need to be converted into Mermaid.js, a format friendly to GitHub for seamless rendering. By doing so, ensure all diagrams preserve their original intent and retain the content structure accurately. Files to inspect and potentially update include: README.md, c4-model.md, erd.md, and flows.md. Verified Mermaid syntax blocks should stay untouched. Additionally, update any text diagrams or code blocks unrecognized by Mermaid so they render properly in GitHub Markdown.

This pull request was created from Copilot chat.

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