migrate to decoupled Blowfish layout, fix TOC scrollspy, and update docs

- Theme Decoupling & Cleanup:
      - Fully decoupled and vendored the Blowfish theme directly into root directories (layouts/,
  assets/, static/, data/, i18n/).
      - De-registered and cleaned up legacy Git submodules (themes/blowfish, themes/hugo-admonitions)
  from the Git index to protect the build from upstream breakages.
      - Configured .gitignore to ignore development preview symlinks (content, static,
  config/_default/menus.en.toml), build folders (public/, resources/), and locks.

    - TOC & Layout Fixes:
      - Replaced the custom layouts/_default/single.html template with the Blowfish default to restore
  native container widths and the side-by-side flex layout.
      - Restored TOC to float on the right sidebar on desktop viewports and render inline on mobile
  viewports.
      - Fixed a parameter resolution bug in layouts/partials/toc.html by checking both .Site.Params.
  smartTOC and .Site.Params.article.smartTOC (where it is defined in params.toml).
      - Upgraded the TOC scrollspy JavaScript to target all '#TableOfContents' containers on the page,
  enabling highlight tracking on both desktop and mobile layouts.

    - Documentation Updates (README.md):
      - Restored YAML front matter metadata block at the top.
      - Added detailed notes on the CI/CD build process and Gitea runner deployment targets
  (/srv/www/docs-public and /srv/www/docs-private).
      - Added a categorized and sorted "Shortcodes Quick Reference" table at the top of the shortcodes
  section (ordered by Custom, Hugo Default, and Blowfish).
      - Documented custom shortcodes (Include, Screenshot, Raw HTML) and missing Hugo default
  shortcodes (Highlight, Instagram, Param, Ref, Relref, Twitter, Vimeo, Youtube).
      - Restructured headings to ensure all sub-shortcodes are H3, removed block break tags (<br/>),
  and appended horizontal separators (---) after H2 sections.

layouts/partials/author-extra.html

@@ -0,0 +1,66 @@
+{{ $disableImageOptimization := .Site.Params.disableImageOptimization | default false }}
+<div class="flex author author-extra mt-4">
+  {{ with .data.image }}
+    {{ $authorImage := "" }}
+    {{ if or (hasPrefix . "http://") (hasPrefix . "https://") }}
+      {{ $authorImage = resources.GetRemote . }}
+    {{ else }}
+      {{ $authorImage = resources.Get . }}
+    {{ end }}
+    {{ if $authorImage }}
+      {{ $final := $authorImage }}
+      {{ $squareImage := $authorImage }}
+      {{ if not (or $disableImageOptimization (eq $authorImage.MediaType.SubType "svg")) }}
+        {{ $final = $authorImage.Fill "192x192" }}
+        {{ $shortSide := int (math.Min $authorImage.Width $authorImage.Height) }}
+        {{ $squareImage = $authorImage.Crop (printf "%dx%d" $shortSide $shortSide ) }}
+      {{ end }}
+      <img
+        class="!mt-0 !mb-0 h-24 w-24 rounded-full me-4"
+        width="96"
+        height="96"
+        alt="{{ $.Site.Params.Author.name | default " Author" }}"
+        src="{{ $final.RelPermalink }}"
+        data-zoom-src="{{ $squareImage.RelPermalink }}" />
+    {{ end }}
+  {{ end }}
+  <div class="place-self-center">
+    {{ $link := .link }}
+    {{ with .data.name | markdownify | emojify }}
+      <div class="text-[0.6rem] uppercase leading-3 text-neutral-500 dark:text-neutral-400">
+        {{ i18n "author.byline_title" | markdownify }}
+      </div>
+      <a
+        {{ if $link }}href="{{ $link }}"{{ end }}
+        class="font-semibold leading-6 text-neutral-800 dark:text-neutral-300">
+        {{ . }}
+      </a>
+    {{ end }}
+    {{ with .data.bio | markdownify }}
+      <div class="text-sm text-neutral-700 dark:text-neutral-400">{{ . }}</div>
+    {{ end }}
+    <div class="text-2xl sm:text-lg">
+      <div class="flex flex-wrap text-neutral-400 dark:text-neutral-500 space-x-2">
+        {{ range .data.social }}
+          {{ range $name, $link := . }}
+            {{ $isEmail := eq $name "email" }}
+            <a
+              class="{{ cond $isEmail "email-link" "" }} hover:text-primary-700 dark:hover:text-primary-400"
+              href="{{ cond $isEmail "#" ($link | safeURL) }}"
+              {{ if $isEmail }}
+                data-email="{{ $link | base64Encode }}" data-subject="Contact"
+              {{ end }}
+              target="_blank"
+              aria-label="{{ $name | title }}"
+              title="{{ $name | title }}"
+              rel="me noopener noreferrer">
+              <span class="inline-block align-text-bottom">
+                {{ partial "icon.html" $name }}
+              </span>
+            </a>
+          {{ end }}
+        {{ end }}
+      </div>
+    </div>
+  </div>
+</div>