Eliminate dual-source content model

CLAUDE.md

@@ -46,7 +46,7 @@ assets/
   banners/
   doc/
   uml/
-astro-site/                # Astro build (imports from chapters/ and assets/)
+astro-site/                # Astro build (reads directly from chapters/)
 docs/                      # Legacy MkDocs content (reference, not active)
   solid-ai-templates/      # Submodule — Imbra-Ltd/solid-ai-templates
 ```
@@ -109,6 +109,9 @@ Every chapter follows this structure:
 
 - Reference other chapters by file: `[Building Blocks](02-building-blocks.md)`
 - Reference sections within a chapter by heading anchor: `[Tag Object](#tag-object-labels)`
+- The remark plugin (`astro-site/src/plugins/remark-rewrite-links.ts`)
+  rewrites `NN-slug.md` links to `../slug/` at build time — no manual
+  sync needed
 
 ### Images
 

astro-site/astro.config.mjs

@@ -1,5 +1,6 @@
 // @ts-check
 import { defineConfig } from 'astro/config';
+import { remarkRewriteLinks } from './src/plugins/remark-rewrite-links.ts';
 
 // https://astro.build/config
 export default defineConfig({
@@ -8,5 +9,6 @@ export default defineConfig({
   trailingSlash: 'always',
   markdown: {
     syntaxHighlight: false,
+    remarkPlugins: [remarkRewriteLinks],
   },
 });

astro-site/src/content.config.ts

@@ -4,7 +4,7 @@ import { glob } from "astro/loaders";
 const docs = defineCollection({
   loader: glob({
     pattern: "**/*.md",
-    base: "./src/content/docs",
+    base: "../chapters",
     generateId: ({ entry }) => entry.replace(/\.md$/, ""),
   }),
   schema: z.object({