feat(docs-site): add starlight-plugin-icons, use real Gitea logo in header

The header social link used Starlight's generic `code-branch` icon.
Wires up starlight-plugin-icons + UnoCSS (Iconify) and overrides
SocialIcons to render `pajamas:gitea` for the Gitea link instead, while
falling back to Starlight's default icon set for anything else. Sidebar
and codeblock icon support are enabled but unused for now.

docs/site/astro.config.mjs

@@ -1,5 +1,6 @@
 import { defineConfig } from 'astro/config';
-import starlight from '@astrojs/starlight';
+import UnoCSS from 'unocss/astro';
+import Icons from 'starlight-plugin-icons';
 import starlightLinksValidator from 'starlight-links-validator';
 import starlightCatppuccin from '@catppuccin/starlight';
 import starlightLlmsTxt from 'starlight-llms-txt';
@@ -9,45 +10,54 @@ export default defineConfig({
   prerenderConflictBehavior: 'ignore',
   site: 'https://fish.rootiest.fyi',
   integrations: [
-    starlight({
-      title: 'Rootiest Fish Config',
-      description: 'Reference manual for the rootiest fish configuration.',
-      favicon: '/favicon.svg',
-      logo: {
-        src: './src/assets/logo.svg',
+    UnoCSS(),
+    ...Icons({
+      sidebar: true,
+      codeblock: true,
+      extractSafelist: true,
+      starlight: {
+        title: 'Rootiest Fish Config',
+        description: 'Reference manual for the rootiest fish configuration.',
+        favicon: '/favicon.svg',
+        logo: {
+          src: './src/assets/logo.svg',
+        },
+        social: [
+          {
+            icon: 'code-branch',
+            label: 'Gitea',
+            href: 'https://git.rootiest.dev/rootiest/fish-config',
+          },
+        ],
+        components: {
+          SocialIcons: './src/components/starlight/SocialIcons.astro',
+        },
+        head: [
+          {
+            tag: 'script',
+            content: 'document.addEventListener("DOMContentLoaded", () => { document.querySelectorAll("starlight-file-tree").forEach(tree => { tree.querySelectorAll("details").forEach((d, i) => { if (i !== 0) d.removeAttribute("open"); }); }); });',
+          },
+        ],
+        plugins: [
+          starlightLinksValidator(),
+          starlightCatppuccin({
+            dark: { flavor: "mocha", accent: "green" },
+            light: { flavor: "latte", accent: "sky" },
+          }),
+          starlightLlmsTxt(),
+        ],
+        expressiveCode: {
+          // Shiki ships both Catppuccin flavours; Starlight picks by the
+          // reader's colour scheme, matching the palette in catppuccin.css.
+          themes: ['catppuccin-mocha', 'catppuccin-latte'],
+          styleOverrides: {
+            borderRadius: '0.4rem',
+            borderColor: 'var(--sl-color-gray-5)',
+            codeFontSize: '0.875rem',
+          },
+        },
+        sidebar,
       },
-      social: [
-        {
-          icon: 'code-branch',
-          label: 'Gitea',
-          href: 'https://git.rootiest.dev/rootiest/fish-config',
-        },
-      ],
-      head: [
-        {
-          tag: 'script',
-          content: 'document.addEventListener("DOMContentLoaded", () => { document.querySelectorAll("starlight-file-tree").forEach(tree => { tree.querySelectorAll("details").forEach((d, i) => { if (i !== 0) d.removeAttribute("open"); }); }); });',
-        },
-      ],
-      plugins: [
-        starlightLinksValidator(),
-        starlightCatppuccin({
-          dark: { flavor: "mocha", accent: "green" },
-          light: { flavor: "latte", accent: "sky" },
-        }),
-        starlightLlmsTxt(),
-      ],
-      expressiveCode: {
-        // Shiki ships both Catppuccin flavours; Starlight picks by the
-        // reader's colour scheme, matching the palette in catppuccin.css.
-        themes: ['catppuccin-mocha', 'catppuccin-latte'],
-        styleOverrides: {
-          borderRadius: '0.4rem',
-          borderColor: 'var(--sl-color-gray-5)',
-          codeFontSize: '0.875rem',
-        },
-      },
-      sidebar,
     }),
   ],
 });