feat: complete MDX migration for blog, fix diagram fidelity and refactor styling architecture

apps/web/content/blog/test-mermaid.mdx

@@ -0,0 +1,22 @@
+---
+title: "Test Mermaid"
+description: "Testing Mermaid rendering"
+date: "2026-01-01"
+tags: ["test"]
+---
+
+Test 1: Plain string attribute (NO quotes in graph content):
+
+<Mermaid id="test-1" title="Test Plain Multiline" showShare={false}>
+graph TD
+    A-->B
+    B-->C
+</Mermaid>
+
+Test 2: Children as raw text (no template literal):
+
+<Mermaid id="test-2" title="Test Raw Children" showShare={false}>
+graph TD
+    D-->E
+    E-->F
+</Mermaid>