feat(BlockEditor): add image alignment, link, and replace/delete controls

- add align (left/center/right/full), href, newTab fields to image block
- render floating toolbar on image hover with alignment buttons and link popover
- add replace and delete actions to image toolbar
- wrap image in <a> in disabled mode and HTML export when href is set
- update htmlToBlocks/blocksToHtml to serialize/parse align, href, newTab
- guard handleContainerMouseDown to prevent multi-block selection on input/textarea focus
- add alignment and link icons to shared icons index
- update README with image block spec and toolbar behaviour

src/shared/components/BlockEditor/inline/clipboard.js

@@ -89,10 +89,31 @@ function blockToElement(block) {
   }
   if (block.type === 'image') {
     const fig = document.createElement('figure');
+    const align = block.align || 'center';
+    fig.setAttribute('data-align', align);
+    if (align === 'left' || align === 'right' || align === 'center') {
+      // CSS inline minimal pour les destinations qui ignorent data-align.
+      fig.setAttribute('style',
+        align === 'center' ? 'text-align:center'
+        : align === 'left' ? 'text-align:left'
+        : 'text-align:right');
+    }
     const img = document.createElement('img');
     img.setAttribute('src', block.src || '');
     if (block.alt) img.setAttribute('alt', block.alt);
-    fig.appendChild(img);
+    if (align === 'full') img.setAttribute('width', '100%');
+    let imgHost = img;
+    if (block.href) {
+      const a = document.createElement('a');
+      a.setAttribute('href', block.href);
+      if (block.newTab) {
+        a.setAttribute('target', '_blank');
+        a.setAttribute('rel', 'noopener noreferrer');
+      }
+      a.appendChild(img);
+      imgHost = a;
+    }
+    fig.appendChild(imgHost);
     if (block.caption) {
       const cap = document.createElement('figcaption');
       cap.textContent = block.caption;
@@ -270,12 +291,20 @@ function parseChildren(node, out) {
       const img = child.querySelector('img');
       if (img) {
         const cap = child.querySelector('figcaption');
+        const linkEl = img.parentElement?.tagName === 'A' ? img.parentElement : null;
+        const dataAlign = child.getAttribute('data-align');
+        const align = ['left', 'center', 'right', 'full'].includes(dataAlign) ? dataAlign : 'center';
+        const href = linkEl?.getAttribute('href') || '';
+        const newTab = !!href && linkEl?.getAttribute('target') === '_blank';
         out.push({
           id: newBlockId(),
           type: 'image',
           src: img.getAttribute('src') || '',
           alt: img.getAttribute('alt') || '',
           caption: cap?.textContent?.trim() || '',
+          align,
+          href,
+          newTab,
         });
       }
       continue;
@@ -289,6 +318,9 @@ function parseChildren(node, out) {
         src: child.getAttribute('src') || '',
         alt: child.getAttribute('alt') || '',
         caption: '',
+        align: 'center',
+        href: '',
+        newTab: false,
       });
       continue;
     }