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/js/shortcodes/gallery.js

@@ -0,0 +1,39 @@
+function _getDefaultPackeryOptions() {
+  return {
+    percentPosition: true,
+    gutter: 5,
+    resize: true,
+  };
+}
+
+function _getPackeryOptions(nodeGallery) {
+  const defaults = _getDefaultPackeryOptions();
+  const {
+    packeryGutter,
+    packeryPercentPosition,
+    packeryResize,
+  } = nodeGallery.dataset;
+
+  return {
+    percentPosition:
+      packeryPercentPosition !== undefined
+        ? packeryPercentPosition === "true"
+        : defaults.percentPosition,
+    gutter:
+      packeryGutter !== undefined ? parseInt(packeryGutter, 10) : defaults.gutter,
+    resize:
+      packeryResize !== undefined ? packeryResize === "true" : defaults.resize,
+  };
+}
+
+(function init() {
+  window.addEventListener("load", function () {
+    let packeries = [];
+    let nodeGalleries = document.querySelectorAll(".gallery");
+
+    nodeGalleries.forEach((nodeGallery) => {
+      let packery = new Packery(nodeGallery, _getPackeryOptions(nodeGallery));
+      packeries.push(packery);
+    });
+  });
+})();