Give the pulse its own duration, and let the editor fill the screen

The shared duration tokens had been stretched to slow the pulses down, which
also slowed every panel and dock animation and left `motion.ts` out of step
with the CSS. Both are back to 200/300 ms, and the pulses use a new
`--duration-pulse` (500 ms): a message arriving is a signal, not a state
change, and it is the only thing here that should linger. The edge pulse read
its own 300 ms constant, so it now takes the token through `motion.ts` and the
two sides cannot drift again.

The code editor also expands: the same node panel fills the content region
beside the sidebar, the canvas chrome steps aside rather than floating on top,
and the settings above the editor keep a readable width.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016WzrvW7rjQbynnhF6pxh6i

frontend/src/components/Flow/NodePanel.tsx

@@ -1,5 +1,5 @@
 import { useQuery } from "@tanstack/react-query"
-import { X } from "lucide-react"
+import { Maximize2, Minimize2, X } from "lucide-react"
 import { lazy, Suspense, useEffect, useRef, useState } from "react"
 
 import type { DType, MessageSpec, NodeDef_Input, NodeTypeInfo } from "@/client"
@@ -22,6 +22,7 @@ import {
   SelectValue,
 } from "@/components/ui/select"
 import { Switch } from "@/components/ui/switch"
+import { cn } from "@/lib/utils"
 import { nodeSourceQueryOptions } from "./queries"
 import { PANEL_SECTION, SidePanel } from "./SidePanel"
 
@@ -276,15 +277,19 @@ function PanelBody({
   flow,
   nodeType,
   suggestions,
+  expanded,
   onChange,
   onSaveSource,
+  onToggleExpand,
 }: {
   node: NodeDef_Input
   flow: string
   nodeType: NodeTypeInfo | undefined
   suggestions: PortSuggestions
+  expanded: boolean
   onChange: (next: NodeDef_Input) => void
   onSaveSource: (code: string) => void
+  onToggleExpand: () => void
 }) {
   const hasSource = nodeType?.has_source ?? node.type === "python"
   const { data: source } = useQuery({
@@ -320,7 +325,7 @@ function PanelBody({
 
   return (
     <>
-      <div className="grid gap-5 p-4">
+      <div className={cn("grid gap-5 p-4", expanded && "max-w-2xl")}>
         <PortList
           title="Consumes"
           specs={node.requires ?? []}
@@ -346,7 +351,21 @@ function PanelBody({
 
       {hasSource ? (
         <div className="flex min-h-[280px] flex-1 flex-col gap-2 px-4 pb-4">
-          <span className={SECTION}>Code</span>
+          <div className="flex items-center justify-between">
+            <span className={SECTION}>Code</span>
+            <Button
+              variant="ghost"
+              size="icon-sm"
+              className="hidden text-muted-foreground md:inline-flex"
+              onClick={onToggleExpand}
+              aria-label={
+                expanded ? "Collapse the editor" : "Expand the editor"
+              }
+              data-testid="toggle-editor-size"
+            >
+              {expanded ? <Minimize2 /> : <Maximize2 />}
+            </Button>
+          </div>
           <div className="min-h-0 flex-1 overflow-hidden rounded-md border border-border">
             <Suspense
               fallback={
@@ -377,8 +396,10 @@ export function NodePanel({
   flow,
   nodeTypes,
   suggestions,
+  expanded,
   onChange,
   onSaveSource,
+  onToggleExpand,
   onClose,
   onDelete,
 }: {
@@ -386,8 +407,10 @@ export function NodePanel({
   flow: string
   nodeTypes: NodeTypeInfo[]
   suggestions: PortSuggestions
+  expanded: boolean
   onChange: (next: NodeDef_Input) => void
   onSaveSource: (code: string) => void
+  onToggleExpand: () => void
   onClose: () => void
   onDelete: () => void
 }) {
@@ -399,6 +422,7 @@ export function NodePanel({
       label="Node settings"
       testId="node-panel"
       bodyKey={node?.id ?? "none"}
+      expanded={expanded}
       onClose={onClose}
       header={
         node ? (
@@ -429,8 +453,10 @@ export function NodePanel({
           flow={flow}
           nodeType={nodeType}
           suggestions={suggestions}
+          expanded={expanded}
           onChange={onChange}
           onSaveSource={onSaveSource}
+          onToggleExpand={onToggleExpand}
         />
       ) : null}
     </SidePanel>