fix: disable problematic Gatsby flags and configure MDX plugin

- Disable PARALLEL_SOURCING to reduce memory pressure during node processing
- Disable DEV_SSR to avoid SSR-related buffer issues during development
- Add explicit mdxOptions configuration to gatsby-plugin-mdx to ensure compatibility

Author: leecalcote

gatsby-config.js

@@ -13,7 +13,8 @@ module.exports = {
   },
   flags: {
     FAST_DEV: true,
-    PARALLEL_SOURCING: true,
+    PARALLEL_SOURCING: false, // Disable parallel sourcing to reduce memory pressure
+    DEV_SSR: false, // Disable SSR to avoid build issues
   },
   trailingSlash: "never",
   plugins: [
@@ -473,6 +474,11 @@ module.exports = {
       resolve: "gatsby-plugin-mdx",
       options: {
         extensions: [".mdx", ".md"],
+        mdxOptions: {
+          remarkPlugins: [],
+          rehypePlugins: [],
+        },
+        gatsbyRemarkPlugins: [],
       },
     },
     {
@@ -631,4 +637,4 @@ module.exports = {
     "gatsby-plugin-meta-redirect",
     // make sure this is always the last one
   ],
-};
+};