[4dwaffle]

Summary

• Document custom resource image icons with C# and TypeScript examples, AppHost-relative paths, explicit favicon reuse, supported formats, file limits, and icon precedence.
• Companion to Support custom resource image icons in the dashboard aspire#21937. Keep this draft until the implementation and corresponding SDK support are available; the new method is not in the published API catalog yet.

Third-party links and affiliations

None.

Validation

• Astro content sync and MDX compilation passed; git diff --check passed.
• Checked documented behavior against the implementation and its regression tests.
• Full site/browser preview and TypeScript runtime execution were not run.