Implement client-side file scanning via Electron IPC with gitignore

- Add fs:scanDirectory IPC handler in main process
- Scan workspace recursively with proper gitignore support
- Use 'ignore' library for accurate gitignore pattern matching
- Expose scanDirectory via electronAPI in preload
- Call IPC from renderer instead of direct fs access
- Cache scanned files for fast filtering
- Scroll to top and highlight first item on results update
- Always exclude .git and node_modules directories

electron/main/ipc.ts

@@ -1,6 +1,9 @@
 import { ipcMain, BrowserWindow } from "electron"
 import { processManager } from "./process-manager"
 import { randomBytes } from "crypto"
+import * as fs from "fs"
+import * as path from "path"
+import ignore from "ignore"
 
 interface Instance {
   id: string
@@ -80,4 +83,49 @@ export function setupInstanceIPC(mainWindow: BrowserWindow) {
   ipcMain.handle("instance:list", async () => {
     return Array.from(instances.values())
   })
+
+  ipcMain.handle("fs:scanDirectory", async (event, workspaceFolder: string) => {
+    const ig = ignore()
+    ig.add([".git", "node_modules"])
+
+    const gitignorePath = path.join(workspaceFolder, ".gitignore")
+    if (fs.existsSync(gitignorePath)) {
+      const content = fs.readFileSync(gitignorePath, "utf-8")
+      ig.add(content)
+    }
+
+    function scanDir(dirPath: string, baseDir: string): string[] {
+      const results: string[] = []
+
+      try {
+        const entries = fs.readdirSync(dirPath, { withFileTypes: true })
+
+        for (const entry of entries) {
+          const fullPath = path.join(dirPath, entry.name)
+          const relativePath = path.relative(baseDir, fullPath)
+
+          if (ig.ignores(relativePath)) {
+            continue
+          }
+
+          if (entry.isDirectory()) {
+            const dirWithSlash = relativePath + "/"
+            if (!ig.ignores(dirWithSlash)) {
+              results.push(dirWithSlash)
+              const subFiles = scanDir(fullPath, baseDir)
+              results.push(...subFiles)
+            }
+          } else {
+            results.push(relativePath)
+          }
+        }
+      } catch (error) {
+        console.warn(`Error scanning ${dirPath}:`, error)
+      }
+
+      return results
+    }
+
+    return scanDir(workspaceFolder, workspaceFolder)
+  })
 }

electron/preload/index.ts

@@ -14,6 +14,7 @@ export interface ElectronAPI {
     }) => void,
   ) => void
   onNewInstance: (callback: () => void) => void
+  scanDirectory: (workspaceFolder: string) => Promise<string[]>
 }
 
 const electronAPI: ElectronAPI = {
@@ -35,6 +36,7 @@ const electronAPI: ElectronAPI = {
   onNewInstance: (callback) => {
     ipcRenderer.on("menu:newInstance", () => callback())
   },
+  scanDirectory: (workspaceFolder: string) => ipcRenderer.invoke("fs:scanDirectory", workspaceFolder),
 }
 
 contextBridge.exposeInMainWorld("electronAPI", electronAPI)