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.

assets/css/components/a11y.css

@@ -0,0 +1,77 @@
+.a11y-panel-enter-active {
+  animation: slideInFromTop 0.3s cubic-bezier(0.4, 0, 0.2, 1) forwards;
+}
+
+.a11y-panel-leave-active {
+  animation: slideOutToTop 0.3s cubic-bezier(0.4, 0, 0.2, 1) forwards;
+}
+
+.ios-toggle {
+  position: relative;
+  width: 42px;
+  height: 24px;
+  background: #e5e5e5;
+  border-radius: 12px;
+  cursor: pointer;
+  transition: background-color 0.3s ease;
+  pointer-events: auto;
+}
+
+.ios-toggle input {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  opacity: 0;
+  cursor: pointer;
+  z-index: 1;
+}
+
+.ios-toggle::after {
+  content: "";
+  position: absolute;
+  top: 2px;
+  left: 2px;
+  width: 20px;
+  height: 20px;
+  background: white;
+  border-radius: 50%;
+  transition:
+    transform 0.3s ease,
+    background-color 0.3s ease;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
+  z-index: 0;
+}
+
+.ios-toggle input:checked + .toggle-track::after {
+  transform: translateX(18px);
+}
+
+.ios-toggle input:checked + .toggle-track {
+  background: rgba(var(--color-primary-500), 1);
+}
+
+.ios-toggle input:checked ~ .ios-toggle-ball {
+  transform: translateX(18px);
+}
+
+.ios-toggle.is-checked {
+  background: rgba(var(--color-primary-500), 1);
+}
+
+.ios-toggle:has(input:checked) {
+  background: rgba(var(--color-primary-500), 1);
+}
+
+.ios-toggle:has(input:checked)::after {
+  transform: translateX(18px);
+}
+
+.dark .ios-toggle {
+  background: #404040;
+}
+
+.dark .ios-toggle::after {
+  background: #f5f5f5;
+}