fix: replace eleventy-plugin-footnotes with markdown-it-footnote

Switch from KittyGiraudel's shortcode-based footnotes plugin to
markdown-it-footnote, which handles standard [^1] Markdown syntax
used in Obsidian notes. Remove the {% footnotes %} shortcode from
the post layout as the plugin renders footnotes automatically.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_includes/layouts/post.njk

@@ -100,9 +100,6 @@ withBlogSidebar: true
   {# Rich reply context with h-cite microformat #}
   {% include "components/reply-context.njk" %}
 
-  {# Footnotes collected from {% footnoteref %} shortcodes in the content #}
-  {% footnotes %}
-
   {# AI usage disclosure — articles and notes only #}
   {% if '/articles/' in page.url or '/notes/' in page.url %}
   <details class="mt-4 text-xs text-surface-700 dark:text-surface-300">

eleventy.config.js

@@ -6,6 +6,7 @@ import { eleventyImageTransformPlugin } from "@11ty/eleventy-img";
 import sitemap from "@quasibit/eleventy-plugin-sitemap";
 import markdownIt from "markdown-it";
 import markdownItAnchor from "markdown-it-anchor";
+import markdownItFootnote from "markdown-it-footnote";
 import syntaxHighlight from "@11ty/eleventy-plugin-syntaxhighlight";
 import { minify } from "html-minifier-terser";
 import { minify as minifyJS } from "terser";
@@ -20,7 +21,6 @@ import { fileURLToPath } from "url";
 
 const esmRequire = createRequire(import.meta.url);
 const postGraph = esmRequire("@rknightuk/eleventy-plugin-post-graph");
-const pluginFootnotes = esmRequire("eleventy-plugin-footnotes");
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const siteUrl = process.env.SITE_URL || "https://example.com";
@@ -99,6 +99,7 @@ export default function (eleventyConfig) {
     linkify: true,  // Auto-convert URLs to clickable links
     typographer: true,
   });
+  md.use(markdownItFootnote);
   md.use(markdownItAnchor, {
     permalink: markdownItAnchor.permalink.headerLink(),
     slugify: (s) => s.toLowerCase().replace(/[^\w\s-]/g, "").replace(/[\s_-]+/g, "-").replace(/^-+|-+$/g, ""),
@@ -155,9 +156,7 @@ export default function (eleventyConfig) {
   // Mermaid diagram support — renders ```mermaid code blocks as diagrams
   eleventyConfig.addPlugin(pluginMermaid);
 
-  // Accessible footnotes — {% footnoteref "id" "note text" %}…{% endfootnoteref %}
+  // markdown-it-footnote handles standard [^1] Markdown footnote syntax
-  // Render collected footnotes with {% footnotes %} in the post layout.
-  eleventyConfig.addPlugin(pluginFootnotes);
 
   // Post graph — GitHub-style contribution grid for posting frequency
   eleventyConfig.addPlugin(postGraph, {

package-lock.json

@@ -33,6 +33,7 @@
         "lite-youtube-embed": "^0.3.2",
         "markdown-it": "^14.1.1",
         "markdown-it-anchor": "^9.2.0",
+        "markdown-it-footnote": "^4.0.0",
         "pagefind": "^1.3.0",
         "rss-parser": "^3.13.0",
         "satori": "^0.19.2",
@@ -4082,6 +4083,12 @@
         "markdown-it": "*"
       }
     },
+    "node_modules/markdown-it-footnote": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/markdown-it-footnote/-/markdown-it-footnote-4.0.0.tgz",
+      "integrity": "sha512-WYJ7urf+khJYl3DqofQpYfEYkZKbmXmwxQV8c8mO/hGIhgZ1wOe7R4HLFNwqx7TjILbnC98fuyeSsin19JdFcQ==",
+      "license": "MIT"
+    },
     "node_modules/markdown-it/node_modules/entities": {
       "version": "4.5.0",
       "resolved": "https://registry.npmjs.org/entities/-/entities-4.5.0.tgz",

package.json

@@ -36,6 +36,7 @@
     "lite-youtube-embed": "^0.3.2",
     "markdown-it": "^14.1.1",
     "markdown-it-anchor": "^9.2.0",
+    "markdown-it-footnote": "^4.0.0",
     "pagefind": "^1.3.0",
     "rss-parser": "^3.13.0",
     "satori": "^0.19.2",