fix: enable flow graph drag-drop and Windows CLI detection

crates/diffcore-core/src/llm/mod.rs

@@ -179,9 +179,40 @@ pub(crate) fn resolve_cli_executable(binary: &str) -> Option<PathBuf> {
 
 fn find_binary_in_path(binary: &str) -> Option<PathBuf> {
     let path_var = std::env::var_os("PATH")?;
-    std::env::split_paths(&path_var)
-        .map(|entry| entry.join(binary))
-        .find(|path| is_executable_file(path))
+
+    #[cfg(not(windows))]
+    {
+        std::env::split_paths(&path_var)
+            .map(|entry| entry.join(binary))
+            .find(|path| is_executable_file(path))
+    }
+
+    #[cfg(windows)]
+    {
+        let pathext = std::env::var("PATHEXT")
+            .unwrap_or_else(|_| ".EXE;.CMD;.BAT;.COM;.PS1".to_string());
+        for entry in std::env::split_paths(&path_var) {
+            // Try bare name first
+            let bare = entry.join(binary);
+            if is_executable_file(&bare) {
+                return Some(bare);
+            }
+            // Then try with each PATHEXT extension
+            for ext in pathext.split(';') {
+                let ext = ext.trim();
+                if ext.is_empty() { continue; }
+                let with_ext = entry.join(format!("{binary}{ext}"));
+                if is_executable_file(&with_ext) {
+                    return Some(with_ext);
+                }
+                let lower = entry.join(format!("{binary}{}", ext.to_lowercase()));
+                if is_executable_file(&lower) {
+                    return Some(lower);
+                }
+            }
+        }
+        None
+    }
 }
 
 fn candidate_cli_paths(binary: &str) -> Vec<PathBuf> {
@@ -200,6 +231,30 @@ fn candidate_cli_paths(binary: &str) -> Vec<PathBuf> {
         }
     }
 
+    // Windows: USERPROFILE as home fallback, plus npm global locations
+    #[cfg(windows)]
+    {
+        if let Some(profile) = std::env::var_os("USERPROFILE") {
+            let home = PathBuf::from(profile);
+            let pathext = std::env::var("PATHEXT")
+                .unwrap_or_else(|_| ".EXE;.CMD;.BAT;.COM;.PS1".to_string());
+            let exts: Vec<&str> = pathext.split(';').map(str::trim).filter(|e| !e.is_empty()).collect();
+            for rel in [".npm-global/bin", ".npm/bin", ".local/bin", ".cargo/bin", "bin"] {
+                for ext in &exts {
+                    candidates.push(home.join(rel).join(format!("{binary}{ext}")));
+                    candidates.push(home.join(rel).join(format!("{binary}{}", ext.to_lowercase())));
+                }
+            }
+        }
+        for env in ["APPDATA", "LOCALAPPDATA"] {
+            if let Some(base) = std::env::var_os(env) {
+                let base = PathBuf::from(base);
+                candidates.push(base.join("npm").join(format!("{binary}.cmd")));
+                candidates.push(base.join("npm").join(format!("{binary}.exe")));
+            }
+        }
+    }
+
     for prefix in ["/opt/homebrew/bin", "/usr/local/bin", "/usr/bin"] {
         candidates.push(PathBuf::from(prefix).join(binary));
     }

crates/diffcore-tauri/ui/src/components/FlowGraph.tsx

@@ -9,10 +9,12 @@ import {
   type Node,
   type Edge,
   type NodeMouseHandler,
+  type NodeChange,
   type EdgeProps,
   Position,
   getBezierPath,
   MarkerType,
+  applyNodeChanges,
 } from "@xyflow/react";
 import "@xyflow/react/dist/style.css";
 import dagre from "@dagrejs/dagre";
@@ -399,9 +401,15 @@ export default function FlowGraph({ edges, files, onNodeClick, replayNodeId }: F
 
   const [selectedNodeId, setSelectedNodeId] = useState<string | null>(null);
   const [fullscreen, setFullscreen] = useState(false);
+  const [nodes, setNodes] = useState<Node[]>(initialNodes);
   const containerRef = useRef<HTMLDivElement>(null);
   const reactFlowInstance = useRef<any>(null);
 
+  // Sync nodes when the layout changes (new analysis / group selection)
+  useEffect(() => {
+    setNodes(initialNodes);
+  }, [initialNodes]);
+
   // The "active" node is either the replay node (if replaying) or the user-clicked node
   const activeNodeId = replayNodeId ?? selectedNodeId;
 
@@ -419,15 +427,20 @@ export default function FlowGraph({ edges, files, onNodeClick, replayNodeId }: F
 
   // Track active node for visual highlight + replay glow
   const processedNodes = useMemo(() => {
-    return initialNodes.map((node) => ({
+    return nodes.map((node) => ({
       ...node,
       data: {
         ...node.data,
         selected: node.id === activeNodeId,
         replayActive: replayNodeId != null && node.id === replayNodeId,
       },
     }));
-  }, [initialNodes, activeNodeId, replayNodeId]);
+  }, [nodes, activeNodeId, replayNodeId]);
+
+  // Handle node position changes from dragging
+  const onNodesChange = useCallback((changes: NodeChange[]) => {
+    setNodes((nds) => applyNodeChanges(changes, nds));
+  }, []);
 
   const handleNodeClick: NodeMouseHandler = useCallback(
     (_event, node) => {
@@ -501,6 +514,7 @@ export default function FlowGraph({ edges, files, onNodeClick, replayNodeId }: F
         edges={processedEdges}
         nodeTypes={nodeTypes}
         edgeTypes={edgeTypes}
+        onNodesChange={onNodesChange}
         onNodeClick={handleNodeClick}
         onPaneClick={handlePaneClick}
         onInit={(instance: any) => { reactFlowInstance.current = instance; }}