Add side panels, task selection, graph animation, and project docs

- Foldable left panel (user profile) and right panel (task details)
- Clicking a task in the list or graph node selects it and shows details
- Both views (task list + graph) always mounted via absolute inset-0 for
  correct canvas dimensions; tabs toggle visibility with opacity
- Graph node selection animation: other nodes repel outward (charge -600),
  then selected node smoothly slides to center (500ms cubic ease-out),
  then charge restores to -120 and graph stabilizes
- Graph re-fits on tab switch and panel resize via ResizeObserver
- Fix UUID string IDs throughout (backend returns UUIDs, not integers)
- Add TaskDetailPanel, UserPanel components
- Add CLAUDE.md project documentation

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

frontend/node_modules/parse5/dist/tree-adapters/default.js

@@ -0,0 +1,173 @@
+import { DOCUMENT_MODE } from '../common/html.js';
+export const defaultTreeAdapter = {
+    //Node construction
+    createDocument() {
+        return {
+            nodeName: '#document',
+            mode: DOCUMENT_MODE.NO_QUIRKS,
+            childNodes: [],
+        };
+    },
+    createDocumentFragment() {
+        return {
+            nodeName: '#document-fragment',
+            childNodes: [],
+        };
+    },
+    createElement(tagName, namespaceURI, attrs) {
+        return {
+            nodeName: tagName,
+            tagName,
+            attrs,
+            namespaceURI,
+            childNodes: [],
+            parentNode: null,
+        };
+    },
+    createCommentNode(data) {
+        return {
+            nodeName: '#comment',
+            data,
+            parentNode: null,
+        };
+    },
+    createTextNode(value) {
+        return {
+            nodeName: '#text',
+            value,
+            parentNode: null,
+        };
+    },
+    //Tree mutation
+    appendChild(parentNode, newNode) {
+        parentNode.childNodes.push(newNode);
+        newNode.parentNode = parentNode;
+    },
+    insertBefore(parentNode, newNode, referenceNode) {
+        const insertionIdx = parentNode.childNodes.indexOf(referenceNode);
+        parentNode.childNodes.splice(insertionIdx, 0, newNode);
+        newNode.parentNode = parentNode;
+    },
+    setTemplateContent(templateElement, contentElement) {
+        templateElement.content = contentElement;
+    },
+    getTemplateContent(templateElement) {
+        return templateElement.content;
+    },
+    setDocumentType(document, name, publicId, systemId) {
+        const doctypeNode = document.childNodes.find((node) => node.nodeName === '#documentType');
+        if (doctypeNode) {
+            doctypeNode.name = name;
+            doctypeNode.publicId = publicId;
+            doctypeNode.systemId = systemId;
+        }
+        else {
+            const node = {
+                nodeName: '#documentType',
+                name,
+                publicId,
+                systemId,
+                parentNode: null,
+            };
+            defaultTreeAdapter.appendChild(document, node);
+        }
+    },
+    setDocumentMode(document, mode) {
+        document.mode = mode;
+    },
+    getDocumentMode(document) {
+        return document.mode;
+    },
+    detachNode(node) {
+        if (node.parentNode) {
+            const idx = node.parentNode.childNodes.indexOf(node);
+            node.parentNode.childNodes.splice(idx, 1);
+            node.parentNode = null;
+        }
+    },
+    insertText(parentNode, text) {
+        if (parentNode.childNodes.length > 0) {
+            const prevNode = parentNode.childNodes[parentNode.childNodes.length - 1];
+            if (defaultTreeAdapter.isTextNode(prevNode)) {
+                prevNode.value += text;
+                return;
+            }
+        }
+        defaultTreeAdapter.appendChild(parentNode, defaultTreeAdapter.createTextNode(text));
+    },
+    insertTextBefore(parentNode, text, referenceNode) {
+        const prevNode = parentNode.childNodes[parentNode.childNodes.indexOf(referenceNode) - 1];
+        if (prevNode && defaultTreeAdapter.isTextNode(prevNode)) {
+            prevNode.value += text;
+        }
+        else {
+            defaultTreeAdapter.insertBefore(parentNode, defaultTreeAdapter.createTextNode(text), referenceNode);
+        }
+    },
+    adoptAttributes(recipient, attrs) {
+        const recipientAttrsMap = new Set(recipient.attrs.map((attr) => attr.name));
+        for (let j = 0; j < attrs.length; j++) {
+            if (!recipientAttrsMap.has(attrs[j].name)) {
+                recipient.attrs.push(attrs[j]);
+            }
+        }
+    },
+    //Tree traversing
+    getFirstChild(node) {
+        return node.childNodes[0];
+    },
+    getChildNodes(node) {
+        return node.childNodes;
+    },
+    getParentNode(node) {
+        return node.parentNode;
+    },
+    getAttrList(element) {
+        return element.attrs;
+    },
+    //Node data
+    getTagName(element) {
+        return element.tagName;
+    },
+    getNamespaceURI(element) {
+        return element.namespaceURI;
+    },
+    getTextNodeContent(textNode) {
+        return textNode.value;
+    },
+    getCommentNodeContent(commentNode) {
+        return commentNode.data;
+    },
+    getDocumentTypeNodeName(doctypeNode) {
+        return doctypeNode.name;
+    },
+    getDocumentTypeNodePublicId(doctypeNode) {
+        return doctypeNode.publicId;
+    },
+    getDocumentTypeNodeSystemId(doctypeNode) {
+        return doctypeNode.systemId;
+    },
+    //Node types
+    isTextNode(node) {
+        return node.nodeName === '#text';
+    },
+    isCommentNode(node) {
+        return node.nodeName === '#comment';
+    },
+    isDocumentTypeNode(node) {
+        return node.nodeName === '#documentType';
+    },
+    isElementNode(node) {
+        return Object.prototype.hasOwnProperty.call(node, 'tagName');
+    },
+    // Source code location
+    setNodeSourceCodeLocation(node, location) {
+        node.sourceCodeLocation = location;
+    },
+    getNodeSourceCodeLocation(node) {
+        return node.sourceCodeLocation;
+    },
+    updateNodeSourceCodeLocation(node, endLocation) {
+        node.sourceCodeLocation = { ...node.sourceCodeLocation, ...endLocation };
+    },
+};