Address code review feedback: update branding and fix indentation

Co-authored-by: reindervdw-cmi <200102462+reindervdw-cmi@users.noreply.github.com>

Author: Copilot

.github/workflows/d2-diagrams.yml

@@ -60,21 +60,21 @@ jobs:
             // Create comment body with embedded SVG
             const commentBody = `## 🏗️ Architecture Diagram Updated
 
-            The D2 architecture diagram has been regenerated based on the changes in this PR.
+The D2 architecture diagram has been regenerated based on the changes in this PR.
 
-            ### Production Architecture
+### Production Architecture
 
-            <details>
-            <summary>Click to view diagram</summary>
+<details>
+<summary>Click to view diagram</summary>
 
-            ${svgContent}
+${svgContent}
 
-            </details>
+</details>
 
-            ---
+---
 
-            📥 You can also download the diagram from the [workflow artifacts](https://github.com/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}).
-            `;
+📥 You can also download the diagram from the [workflow artifacts](https://github.com/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}).
+`;
 
             // Find existing comment
             const comments = await github.rest.issues.listComments({

diagrams/README.md

@@ -0,0 +1,47 @@
+# Architecture Diagrams
+
+This directory contains [D2](https://d2lang.com/) diagrams that document the Azure infrastructure for the CTK project.
+
+## Overview
+
+The diagrams are organized into modular files, each representing a specific component of the architecture:
+
+- **`main.d2`** - The main diagram that imports and connects all components
+- **`shared.d2`** - Shared resources (Container Registry)
+- **`network.d2`** - Virtual Network and subnets
+- **`database.d2`** - Cosmos PostgreSQL database with private endpoint
+- **`container_environment.d2`** - Container App Environment
+- **`container_apps.d2`** - All container applications (webapp, cloai_service, ctk_functions, languagetool)
+- **`supporting_services.d2`** - Supporting services (Key Vault, Storage Account, Log Analytics, Application Insights)
+- **`identity.d2`** - Azure Active Directory authentication
+
+## Building Diagrams
+
+The diagrams are automatically built by the GitHub Actions workflow whenever D2 files are modified. The workflow:
+
+1. Installs the D2 CLI
+2. Compiles `main.d2` to `architecture.svg`
+3. Uploads the SVG as a workflow artifact
+4. Posts the diagram as a comment on pull requests
+
+To build locally, install [D2](https://d2lang.com/) and run:
+
+```bash
+d2 diagrams/main.d2 diagrams/output/architecture.svg
+```
+
+## Architecture Notes
+
+- These diagrams focus on the **production environment** only
+- Icons are from [Terrastruct Icons](https://icons.terrastruct.com/)
+- Only the most important connections between services are shown for clarity
+- The diagrams provide a high-level overview, not an exhaustive representation
+
+## Updating Diagrams
+
+When making infrastructure changes:
+
+1. Update the relevant D2 file(s) in this directory
+2. Commit and push your changes
+3. The workflow will automatically regenerate the diagram
+4. Review the updated diagram in the PR comment or workflow artifacts

diagrams/identity.d2

@@ -1,5 +1,5 @@
 # Identity and Authentication
 
-azure_ad: Azure Active Directory\nApp Registration {
+azure_ad: Microsoft Entra ID\nApp Registration {
   icon: https://icons.terrastruct.com/azure%2FIdentity%2F10221-icon-service-Azure-Active-Directory.svg
 }