fix(messages): single image paste + drag-to-resize handles

- Block Quill's default IMG clipboard matcher (prevents double paste)
- Click on image in editor shows blue border + resize handle (bottom-right)
- Drag handle to resize image
- Click outside removes resize wrapper

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

static/js/conversations.js

@@ -1268,7 +1268,63 @@
                 },
             });
 
-            // Handle pasted images — upload to server and insert as <img>
+            // Image resize: click on image in editor to show resize handles
+            state.quill.root.addEventListener('click', function(e) {
+                if (e.target.tagName === 'IMG') {
+                    var img = e.target;
+                    // Remove any existing resize wrapper
+                    document.querySelectorAll('.img-resize-wrapper').forEach(function(w) {
+                        var inner = w.querySelector('img');
+                        if (inner) w.parentNode.replaceChild(inner, w);
+                    });
+                    // Wrap image in resize container
+                    var wrapper = document.createElement('div');
+                    wrapper.className = 'img-resize-wrapper';
+                    wrapper.contentEditable = 'false';
+                    wrapper.style.cssText = 'display:inline-block; position:relative; border:2px solid #3b82f6; padding:2px;';
+                    img.parentNode.insertBefore(wrapper, img);
+                    wrapper.appendChild(img);
+                    // Add resize handle
+                    var handle = document.createElement('div');
+                    handle.style.cssText = 'position:absolute; right:-4px; bottom:-4px; width:12px; height:12px; background:#3b82f6; border-radius:2px; cursor:nwse-resize;';
+                    wrapper.appendChild(handle);
+                    // Drag to resize
+                    handle.addEventListener('mousedown', function(me) {
+                        me.preventDefault();
+                        var startX = me.clientX;
+                        var startW = img.offsetWidth;
+                        function onMove(mm) {
+                            var newW = Math.max(50, startW + (mm.clientX - startX));
+                            img.style.width = newW + 'px';
+                            img.style.height = 'auto';
+                        }
+                        function onUp() {
+                            document.removeEventListener('mousemove', onMove);
+                            document.removeEventListener('mouseup', onUp);
+                        }
+                        document.addEventListener('mousemove', onMove);
+                        document.addEventListener('mouseup', onUp);
+                    });
+                }
+            });
+
+            // Click outside image removes resize wrapper
+            document.addEventListener('click', function(e) {
+                if (!e.target.closest('.img-resize-wrapper') && !e.target.closest('.ql-editor img')) {
+                    document.querySelectorAll('.img-resize-wrapper').forEach(function(w) {
+                        var inner = w.querySelector('img');
+                        if (inner) w.parentNode.replaceChild(inner, w);
+                    });
+                }
+            });
+
+            // Block Quill's default image paste (prevents double insert)
+            var Delta = Quill.import('delta');
+            state.quill.clipboard.addMatcher('IMG', function(node, delta) {
+                return new Delta(); // Remove pasted images from Quill's clipboard processing
+            });
+
+            // Handle pasted images ourselves — upload to server
             state.quill.root.addEventListener('paste', function(e) {
                 var clipboardData = e.clipboardData || window.clipboardData;
                 if (!clipboardData || !clipboardData.items) return;
@@ -1276,10 +1332,9 @@
                     var item = clipboardData.items[i];
                     if (item.type.indexOf('image') !== -1) {
                         e.preventDefault();
-                        e.stopPropagation();
+                        e.stopImmediatePropagation();
                         var file = item.getAsFile();
                         if (file) {
-                            // Upload image as attachment
                             var fd = new FormData();
                             fd.append('image', file, 'pasted-image.png');
                             api('/api/messages/upload-image', 'POST', fd)
@@ -1291,7 +1346,6 @@
                                     }
                                 })
                                 .catch(function(err) {
-                                    // Fallback: insert as base64
                                     var reader = new FileReader();
                                     reader.onload = function(ev) {
                                         var range = state.quill.getSelection(true);
@@ -1304,7 +1358,7 @@
                         return;
                     }
                 }
-            });
+            }, true);
 
             // Typing indicator
             state.quill.on('text-change', function () {