M2: content collections — case studies, blog, RSS, tags, sitemap

Projects + blog as schema-validated content collections; structured case
studies (problem/design/outcome), blog with tag pages, reading time, RSS
feed (drafts excluded), sitemap, and Shiki dual-theme code highlighting.

astro.config.mjs

@@ -1,11 +1,26 @@
 // @ts-check
 import { defineConfig } from "astro/config";
+import sitemap from "@astrojs/sitemap";
 
 import tailwindcss from "@tailwindcss/vite";
 
 // https://astro.build/config
 export default defineConfig({
   site: "https://www.bztmon.com",
+  integrations: [sitemap()],
+  build: {
+    // Keep CSS in external files (no inlined <style> blocks) — friendlier to a strict CSP.
+    inlineStylesheets: "never",
+  },
+  markdown: {
+    shikiConfig: {
+      // Dual theme via CSS variables → colours switch with our data-theme, no
+      // hard-coded per-token colours baked to one theme.
+      themes: { light: "github-light", dark: "github-dark" },
+      defaultColor: false,
+      wrap: true,
+    },
+  },
   vite: {
     plugins: [tailwindcss()],
   },