feat: add blog with archives, pagination, search, sharing and RSS

- Content collection (one folder per post) with zod schema
- /blog, category and tag archives with /sayfa/<n>/ pagination
- Post page: breadcrumbs, date badges, share bar, TOC, DIY notice,
  code copy, license line, prev/next, BlogPosting + BreadcrumbList JSON-LD
- Sidebar: Pagefind search, categories, featured fallback, tag cloud
- Sätteri HAST plugins for figure/figcaption and external links
- Dual-theme Shiki, themed prose, RSS feed, latest posts on home
- Three sample posts marked as examples

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lib/data.ts

@@ -6,6 +6,8 @@ import { z } from 'astro/zod';
 import siteJson from '../data/site.json';
 import socialJson from '../data/social.json';
 import homeJson from '../data/home.json';
+import categoriesJson from '../data/categories.json';
+import blogJson from '../data/blog.json';
 
 const link = z.object({ label: z.string().min(1), href: z.string().min(1) });
 const icon = z.string().startsWith('tabler:');
@@ -111,6 +113,73 @@ const homeSchema = z.object({
   ),
 });
 
+const categoriesSchema = z
+  .array(
+    z.object({
+      slug: z.string().regex(/^[a-z0-9-]+$/),
+      name: z.string(),
+      description: z.string(),
+      icon,
+    }),
+  )
+  .min(1);
+
+/** Object of required string keys; keeps the key names in the inferred type. */
+const strings = <const K extends string>(keys: readonly K[]) =>
+  z.object(Object.fromEntries(keys.map((k) => [k, z.string()])) as Record<K, z.ZodString>);
+
+const blogSchema = z.object({
+  seo: z.object({ title: z.string(), description: z.string().max(160) }),
+  list: strings([
+    'eyebrow',
+    'title',
+    'categoryEyebrow',
+    'tagEyebrow',
+    'tagTitle',
+    'categoryDescription',
+    'tagDescription',
+    'pageTitle',
+    'empty',
+  ]),
+  card: strings(['readMore', 'readingTime']),
+  dates: strings(['created', 'updated']),
+  pager: strings(['label', 'first', 'prev', 'next', 'last', 'page']),
+  sidebar: strings([
+    'label',
+    'search',
+    'searchLabel',
+    'searchPlaceholder',
+    'searchNoResults',
+    'searchResults',
+    'searchUnavailable',
+    'categories',
+    'featured',
+    'tags',
+  ]),
+  post: strings([
+    'breadcrumbLabel',
+    'toc',
+    'shareLabel',
+    'copyLink',
+    'copied',
+    'nativeShare',
+    'copyCode',
+    'codeCopied',
+    'category',
+    'tags',
+    'adjacentLabel',
+    'prev',
+    'next',
+    'license',
+    'licenseName',
+    'licenseHref',
+  ]),
+  diy: z.object({ title: z.string(), body: z.string(), link }),
+  share: z.array(
+    z.object({ id: z.string(), label: z.string(), icon, url: z.string().includes('{url}') }),
+  ),
+});
+
 function parse<T>(name: string, schema: z.ZodType<T>, data: unknown): T {
   const result = schema.safeParse(data);
   if (!result.success) {
@@ -121,8 +190,16 @@ function parse<T>(name: string, schema: z.ZodType<T>, data: unknown): T {
 
 export const site = parse('site.json', siteSchema, siteJson);
 export const home = parse('home.json', homeSchema, homeJson);
+export const categories = parse('categories.json', categoriesSchema, categoriesJson);
+export const blog = parse('blog.json', blogSchema, blogJson);
 export const social = parse('social.json', socialSchema, socialJson).filter((s) => s.href);
 
 export type Site = z.infer<typeof siteSchema>;
 export type HomeSection = (typeof home.sections)[number];
+export type Category = (typeof categories)[number];
 export type SocialLink = (typeof social)[number];
+
+/** Fills `{key}` placeholders in UI strings from the JSON files. */
+export function fmt(template: string, values: Record<string, string | number>): string {
+  return template.replace(/\{(\w+)\}/g, (m, k: string) => (k in values ? String(values[k]) : m));
+}