feat: add full-screen toggle to knowledge graph view

Admin graph view was cramped inside the sidebar-constrained content area, making it hard to inspect and edit larger graphs. Adds a full-screen overlay toggle (button + Esc to exit) that expands the graph/table view and edit panels to fill the viewport.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/components/admin/KnowledgeGraph.jsx

@@ -3,7 +3,7 @@ import * as d3 from 'd3';
 import * as db from '../../lib/db';
 import { callLLM } from '../../lib/llm';
 import { EMIT_GRAPH_ACTIONS_TOOL } from '../../lib/llmTools';
-import { Network, Table2 } from 'lucide-react';
+import { Network, Table2, Maximize2, Minimize2 } from 'lucide-react';
 import { useGraphData } from '../../hooks/useGraphData';
 import { filterAiActions } from '../../lib/graphGuard';
 import GraphControls from './graph/GraphControls';
@@ -87,6 +87,7 @@ const KnowledgeGraph = () => {
   const [analyzeNotice, setAnalyzeNotice] = useState(null); // info-level message from last analyze
   const [isRestoring, setIsRestoring] = useState(false);
   const [viewMode, setViewMode] = useState('graph'); // 'graph' | 'table'
+  const [isFullscreen, setIsFullscreen] = useState(false);
 
   const {
     topics, relations, snapshotMeta,
@@ -96,15 +97,29 @@ const KnowledgeGraph = () => {
   // ── Canvas sizing ────────────────────────────────────────────────────────────
 
   useEffect(() => {
-    if (!wrapperRef.current) return;
     const measure = () => {
+      if (!wrapperRef.current) return;
       const { width, height } = wrapperRef.current.getBoundingClientRect();
-      setDimensions({ width, height });
+      if (width > 0 && height > 0) setDimensions({ width, height });
     };
-    measure();
+    // rAF: toggling view mode / fullscreen resizes the wrapper without firing a
+    // window resize event, so re-measure once the DOM has reflowed.
+    const raf = requestAnimationFrame(measure);
     window.addEventListener('resize', measure);
-    return () => window.removeEventListener('resize', measure);
-  }, []);
+    return () => {
+      cancelAnimationFrame(raf);
+      window.removeEventListener('resize', measure);
+    };
+  }, [viewMode, isFullscreen]);
+
+  // ── Esc exits fullscreen ─────────────────────────────────────────────────────
+
+  useEffect(() => {
+    if (!isFullscreen) return;
+    const onKey = (e) => { if (e.key === 'Escape') setIsFullscreen(false); };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [isFullscreen]);
 
   // ── D3 force graph ───────────────────────────────────────────────────────────
 
@@ -433,7 +448,7 @@ const KnowledgeGraph = () => {
   // ── Render ───────────────────────────────────────────────────────────────────
 
   return (
-    <div className="relative w-full h-full flex flex-col md:flex-row">
+    <div className={`${isFullscreen ? 'fixed inset-0 z-50 bg-paper' : 'relative w-full h-full'} flex flex-col md:flex-row`}>
       {/* Main view: graph canvas or table */}
       <div className="flex-1 flex flex-col border-r border-bg-warm min-w-0">
         {/* View-mode toggle */}
@@ -456,6 +471,13 @@ const KnowledgeGraph = () => {
           >
             <Table2 size={13} /> Table
           </button>
+          <button
+            onClick={() => setIsFullscreen(f => !f)}
+            className="ml-auto flex items-center gap-1.5 px-3 py-1 text-xs rounded-[var(--r-sm)] text-fg-muted hover:bg-bg-warm/50 transition-colors"
+            title={isFullscreen ? 'Exit full screen (Esc)' : 'Full screen'}
+          >
+            {isFullscreen ? <><Minimize2 size={13} /> Exit</> : <><Maximize2 size={13} /> Full screen</>}
+          </button>
         </div>
 
         {viewMode === 'graph' ? (