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/code.js

@@ -0,0 +1,78 @@
+var scriptBundle = document.getElementById("script-bundle");
+var copyText = scriptBundle?.getAttribute("data-copy") || "Copy";
+var copiedText = scriptBundle?.getAttribute("data-copied") || "Copied";
+
+function createCopyButton(highlightWrapper) {
+  const button = document.createElement("button");
+  button.className = "copy-button";
+  button.type = "button";
+  button.ariaLabel = copyText;
+  button.innerText = copyText;
+  button.addEventListener("click", () => copyCodeToClipboard(button, highlightWrapper));
+  highlightWrapper.insertBefore(button, highlightWrapper.firstChild);
+}
+
+async function copyCodeToClipboard(button, highlightWrapper) {
+  const codeToCopy = getCodeText(highlightWrapper);
+
+  function fallback(codeToCopy, highlightWrapper) {
+    const textArea = document.createElement("textArea");
+    textArea.contentEditable = "true";
+    textArea.readOnly = "false";
+    textArea.className = "copy-textarea";
+    textArea.value = codeToCopy;
+    highlightWrapper.insertBefore(textArea, highlightWrapper.firstChild);
+    const range = document.createRange();
+    range.selectNodeContents(textArea);
+    const sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+    textArea.focus();
+    textArea.setSelectionRange(0, 999999);
+    document.execCommand("copy");
+    highlightWrapper.removeChild(textArea);
+  }
+
+  try {
+    result = await navigator.permissions.query({ name: "clipboard-write" });
+    if (result.state == "granted" || result.state == "prompt") {
+      await navigator.clipboard.writeText(codeToCopy);
+    } else {
+      fallback(codeToCopy, highlightWrapper);
+    }
+  } catch (_) {
+    fallback(codeToCopy, highlightWrapper);
+  } finally {
+    button.blur();
+    button.innerText = copiedText;
+    setTimeout(function () {
+      button.innerText = copyText;
+    }, 2000);
+  }
+}
+
+function getCodeText(highlightWrapper) {
+  const highlightDiv = highlightWrapper.querySelector(".highlight");
+  if (!highlightDiv) return "";
+
+  const codeBlock = highlightDiv.querySelector("code");
+  const inlineLines = codeBlock?.querySelectorAll(".cl"); // linenos=inline
+  const tableCodeCell = highlightDiv?.querySelector(".lntable .lntd:last-child code"); // linenos=table
+
+  if (!codeBlock) return "";
+
+  if (inlineLines.length > 0) {
+    const cleanedLines = Array.from(inlineLines).map((line) => line.textContent.replace(/\n$/, ""));
+    return cleanedLines.join("\n");
+  }
+
+  if (tableCodeCell) {
+    return tableCodeCell.textContent.trim();
+  }
+
+  return codeBlock.textContent.trim();
+}
+
+window.addEventListener("DOMContentLoaded", (event) => {
+  document.querySelectorAll(".highlight-wrapper").forEach((highlightWrapper) => createCopyButton(highlightWrapper));
+});