Add a callout in diagram about setting SVG format for PDF

Author: cderv

docs/authoring/diagrams.qmd

@@ -200,6 +200,18 @@ format:
 
 Valid values for `mermaid-format` include `js`, `png`, and `svg`,
 
+::: callout-warning
+## SVG Format Limitations with PDF Output
+
+When rendering to PDF or LaTeX-based formats, `mermaid-format: svg` requires additional tooling and may have rendering issues:
+
+- **Requires installation:** `rsvg-convert` must be available in your system PATH
+- **Potential rendering issues:** Text clipping in diagrams with multi-line labels
+- **Recommended:** Use default `mermaid-format: png` for PDF output
+
+For installation instructions, see [SVG Images](/docs/output-formats/pdf-basics.qmd#svg-images).
+:::
+
 ## Mermaid Themes {#mermaid-theming}
 
 {{< include _mermaid-theming.qmd >}}