refactor: migrate frontend from shadcn/Tailwind to Mantine v9

Reescribe todos los componentes UI para usar Mantine v9 en lugar de shadcn/Tailwind.
Elimina cn(), CVA, components.json, theme_provider custom y globals.css con Tailwind.
Añade 25+ componentes nuevos (AppShell, AuthForm, DatePickerInput, Dropzone, etc.)
y MantineProvider como wrapper estándar del sistema de temas.

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

frontend/functions/ui/graph/index.tsx

@@ -49,6 +49,12 @@ export interface GraphTheme {
   selectionColor?: string
 }
 
+export interface ContextMenuTarget {
+  type: "node" | "edge" | "canvas"
+  id?: string
+  data?: GraphNode | GraphEdge
+}
+
 export interface GraphContainerProps {
   data: GraphData
   layout?: "organic" | "random"
@@ -58,6 +64,7 @@ export interface GraphContainerProps {
   nodeTypes?: NodeType[]
   onNodeClick?: (node: GraphNode) => void
   onNodeDoubleClick?: (node: GraphNode) => void
+  onContextMenu?: (event: MouseEvent, target: ContextMenuTarget) => void
   enableSelection?: boolean
   selectionMode?: "single" | "multiple"
   theme?: GraphTheme
@@ -84,6 +91,7 @@ function GraphContainer({
   nodeTypes = [],
   onNodeClick,
   onNodeDoubleClick,
+  onContextMenu,
   theme: themeProp,
   height = "100%",
   className,
@@ -96,10 +104,30 @@ function GraphContainer({
     [themeProp],
   )
 
-  // Build + render
+  // Build + render — wait for container to have dimensions
+  const [ready, setReady] = React.useState(false)
   React.useEffect(() => {
     const el = containerRef.current
     if (!el) return
+    if (el.clientHeight > 0 && el.clientWidth > 0) {
+      setReady(true)
+      return
+    }
+    const ro = new ResizeObserver((entries) => {
+      for (const entry of entries) {
+        if (entry.contentRect.height > 0 && entry.contentRect.width > 0) {
+          setReady(true)
+          ro.disconnect()
+        }
+      }
+    })
+    ro.observe(el)
+    return () => ro.disconnect()
+  }, [])
+
+  React.useEffect(() => {
+    const el = containerRef.current
+    if (!el || !ready) return
 
     // Cleanup previous instance
     if (sigmaRef.current) {
@@ -110,7 +138,7 @@ function GraphContainer({
     const g = new Graph({ multi: true, type: "directed" })
     graphRef.current = g
 
-    // Add nodes
+    // Add nodes — store entity type as entityType to avoid sigma interpreting it as render program
     for (const n of data.nodes) {
       g.addNode(n.id, {
         label: n.label,
@@ -118,7 +146,7 @@ function GraphContainer({
         y: n.y ?? (Math.random() - 0.5) * 10,
         size: n.size ?? theme.nodeSize,
         color: n.color ?? theme.nodeColor,
-        type: n.type,
+        entityType: n.type,
       })
     }
 
@@ -152,6 +180,7 @@ function GraphContainer({
 
     // Render
     const renderer = new Sigma(g, el, {
+      allowInvalidContainer: true,
       renderEdgeLabels: false,
       defaultEdgeColor: theme.edgeColor,
       defaultNodeColor: theme.nodeColor,
@@ -174,13 +203,30 @@ function GraphContainer({
         onNodeDoubleClick({ id: node, ...attrs } as unknown as GraphNode)
       })
     }
+    if (onContextMenu) {
+      renderer.on("rightClickNode", ({ node, event }) => {
+        const mouseEvent = event.original as MouseEvent
+        mouseEvent.preventDefault()
+        const attrs = g.getNodeAttributes(node)
+        onContextMenu(mouseEvent, {
+          type: "node",
+          id: node,
+          data: { id: node, ...attrs } as unknown as GraphNode,
+        })
+      })
+      renderer.on("rightClickStage", ({ event }) => {
+        const mouseEvent = event.original as MouseEvent
+        mouseEvent.preventDefault()
+        onContextMenu(mouseEvent, { type: "canvas" })
+      })
+    }
 
     return () => {
       renderer.kill()
       sigmaRef.current = null
       graphRef.current = null
     }
-  }, [data, layout, theme, onNodeClick, onNodeDoubleClick])
+  }, [data, layout, theme, onNodeClick, onNodeDoubleClick, onContextMenu, ready])
 
   // Container background
   const containerStyle: React.CSSProperties = {