feat(wysiwyg): Add language selection for code blocks, block settings menu, fix cursor navigation, and update demo to use dees-panel

- Added modal to select programming language when creating code blocks
- Added settings button (3 dots) on each block for configuration
- Fixed cursor not jumping to new block after pressing Enter
- Special handling for code blocks: Enter creates new line, Shift+Enter creates new block
- Display language indicator on code blocks
- Updated demo to use dees-panel instead of demo-section divs
- Added language selection in block settings modal for existing code blocks

ts_web/elements/wysiwyg/wysiwyg.blocks.ts

@@ -55,6 +55,30 @@ export class WysiwygBlocks {
       `;
     }
     
+    // Special rendering for code blocks with language indicator
+    if (block.type === 'code') {
+      const language = block.metadata?.language || 'plain text';
+      return html`
+        <div class="code-block-container">
+          <div class="code-language">${language}</div>
+          <div
+            class="block ${block.type} ${isSelected ? 'selected' : ''}"
+            contenteditable="true"
+            @input="${handlers.onInput}"
+            @keydown="${handlers.onKeyDown}"
+            @focus="${handlers.onFocus}"
+            @blur="${handlers.onBlur}"
+            @compositionstart="${handlers.onCompositionStart}"
+            @compositionend="${handlers.onCompositionEnd}"
+            @mouseup="${(e: MouseEvent) => {
+              console.log('Block mouseup event fired');
+              if (handlers.onMouseUp) handlers.onMouseUp(e);
+            }}"
+          ></div>
+        </div>
+      `;
+    }
+    
     return html`
       <div
         class="block ${block.type} ${isSelected ? 'selected' : ''}"