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/impls/hooks/admonition-maps.html

@@ -0,0 +1,34 @@
+{{- /* Override this file in your site to customize admonition type aliases and icon mappings */ -}}
+{{- return dict
+  "typeMap" (dict
+    "attention" "warning"
+    "check" "success"
+    "cite" "quote"
+    "done" "success"
+    "error" "danger"
+    "fail" "failure"
+    "faq" "question"
+    "hint" "tip"
+    "help" "question"
+    "missing" "failure"
+    "summary" "abstract"
+    "tldr" "abstract"
+  )
+  "iconMap" (dict
+    "abstract" "file-lines"
+    "bug" "bug"
+    "caution" "fire"
+    "danger" "fire"
+    "example" "list-ol"
+    "failure" "xmark"
+    "important" "star"
+    "info" "circle-info"
+    "note" "circle-info"
+    "success" "check"
+    "todo" "list-check"
+    "tip" "lightbulb"
+    "question" "circle-question"
+    "quote" "quote-left"
+    "warning" "triangle-exclamation"
+  )
+-}}