Add version logging, Markdown card menu item, and oembed card types

- sx-editor prints version on init: [sx-editor] v2026-03-02b-exorcism
- Add Markdown to card insert menu with /markdown and /md slash commands
- Add YouTube, X/Twitter, Vimeo, Spotify, CodePen as dedicated embed
  menu items with brand icons (all create ~kg-embed cards)

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

shared/static/scripts/sx-editor.js

@@ -40,14 +40,20 @@
     ]},
     { section: "Text", items: [
       { type: "html",     icon: "fa-solid fa-code",          label: "HTML",    desc: "Insert raw HTML", slash: ["html"] },
+      { type: "markdown", icon: "fa-brands fa-markdown",     label: "Markdown",desc: "Insert markdown content", slash: ["markdown", "md"] },
       { type: "hr",       icon: "fa-solid fa-minus",         label: "Divider", desc: "Insert a dividing line", slash: ["divider", "hr"] },
       { type: "callout",  icon: "fa-regular fa-comment-dots",label: "Callout", desc: "Info box that stands out", slash: ["callout"] },
       { type: "toggle",   icon: "fa-solid fa-caret-down",    label: "Toggle",  desc: "Collapsible content", slash: ["toggle"] },
       { type: "code",     icon: "fa-solid fa-terminal",      label: "Code",    desc: "Insert a code block", slash: ["code", "codeblock"] },
     ]},
     { section: "Embed", items: [
+      { type: "youtube",  icon: "fa-brands fa-youtube",      label: "YouTube", desc: "Embed a YouTube video", slash: ["youtube", "yt"] },
+      { type: "twitter",  icon: "fa-brands fa-x-twitter",    label: "X (Twitter)", desc: "Embed a tweet", slash: ["twitter", "tweet", "x"] },
+      { type: "vimeo",    icon: "fa-brands fa-vimeo-v",      label: "Vimeo",   desc: "Embed a Vimeo video", slash: ["vimeo"] },
+      { type: "spotify",  icon: "fa-brands fa-spotify",      label: "Spotify", desc: "Embed a Spotify track or playlist", slash: ["spotify"] },
+      { type: "codepen",  icon: "fa-brands fa-codepen",      label: "CodePen", desc: "Embed a CodePen", slash: ["codepen"] },
       { type: "bookmark", icon: "fa-solid fa-bookmark",      label: "Bookmark",desc: "Embed a link as a visual bookmark", slash: ["bookmark"] },
-      { type: "embed",    icon: "fa-solid fa-link",          label: "Other...",desc: "Embed a URL via oEmbed", slash: ["embed", "youtube", "vimeo", "twitter", "spotify", "codepen"] },
+      { type: "embed",    icon: "fa-solid fa-link",          label: "Other...",desc: "Embed any URL via oEmbed", slash: ["embed", "oembed"] },
       { type: "button",   icon: "fa-solid fa-square",        label: "Button",  desc: "Add a button", slash: ["button", "cta"] },
     ]},
   ];
@@ -1790,6 +1796,11 @@
       insertBlockNode(editor, block, refBlock);
       block.querySelector(".sx-card-preview").click();
       return;
+    } else if (type === "markdown") {
+      block = createCardBlock("kg-md", { _childrenSx: '""' });
+      insertBlockNode(editor, block, refBlock);
+      block.querySelector(".sx-card-preview").click();
+      return;
     } else if (type === "button") {
       block = createCardBlock("kg-button", { url: "", text: "Click here", alignment: "center" });
       insertBlockNode(editor, block, refBlock);
@@ -1800,7 +1811,8 @@
       insertBlockNode(editor, block, refBlock);
       block.querySelector(".sx-card-preview").click();
       return;
-    } else if (type === "embed") {
+    } else if (type === "embed" || type === "youtube" || type === "vimeo" ||
+               type === "twitter" || type === "spotify" || type === "codepen") {
       block = createCardBlock("kg-embed", {});
       insertBlockNode(editor, block, refBlock);
       block.querySelector(".sx-card-preview").click();
@@ -2453,11 +2465,16 @@
   // Export
   // =========================================================================
 
+  var VERSION = "2026-03-02b-exorcism";
+
   window.SxEditor = {
+    VERSION: VERSION,
     mount: mount,
     _serializeBlocks: serializeBlocks,
     _serializeInline: serializeInline,
     _deserializeSx: deserializeSx
   };
 
+  console.log("[sx-editor] v" + VERSION + " init");
+
 })();