Allow folders in file picker and use them as search filters

- Remove directory filtering from file picker
- When folder selected, insert folder path into input (not as attachment)
- Folder path becomes search query to filter files in that folder
- Files still create attachments as before
- User can navigate folder structure using @ mentions

src/components/file-picker.tsx

@@ -48,14 +48,12 @@ const FilePicker: Component<FilePickerProps> = (props) => {
       console.log(`[FilePicker] Git files response received in ${elapsed}ms:`, gitResponse)
 
       if (gitResponse?.data && gitResponse.data.length > 0) {
-        const gitFiles: FileItem[] = gitResponse.data
-          .filter((file: any) => !file.path.endsWith("/"))
-          .map((file: any) => ({
-            path: file.path,
-            added: file.added,
-            removed: file.removed,
-            isGitFile: true,
-          }))
+        const gitFiles: FileItem[] = gitResponse.data.map((file: any) => ({
+          path: file.path,
+          added: file.added,
+          removed: file.removed,
+          isGitFile: true,
+        }))
         console.log(`[FilePicker] Cached ${gitFiles.length} git files`)
         setCachedGitFiles(gitFiles)
       } else {
@@ -93,23 +91,21 @@ const FilePicker: Component<FilePickerProps> = (props) => {
         console.log(`[FilePicker] Search response received in ${elapsed}ms:`, searchResponse)
 
         searchFiles = (searchResponse?.data || [])
-          .filter((path: string) => !path.endsWith("/"))
           .filter((path: string) => !gitFiles.some((gf) => gf.path === path))
           .map((path: string) => ({
             path,
             isGitFile: false,
           }))
       } else {
-        console.log(`[FilePicker] Empty query, fetching all files with wildcard`)
+        console.log(`[FilePicker] Empty query, fetching all files`)
         const searchResponse = await props.instanceClient.find.files({
-          query: { query: "." },
+          query: { query: "" },
         })
         const elapsed = Date.now() - startTime
 
         console.log(`[FilePicker] All files response received in ${elapsed}ms:`, searchResponse)
 
         searchFiles = (searchResponse?.data || [])
-          .filter((path: string) => !path.endsWith("/"))
           .filter((path: string) => !gitFiles.some((gf) => gf.path === path))
           .map((path: string) => ({
             path,

src/components/prompt-input.tsx

@@ -317,8 +317,36 @@ export default function PromptInput(props: PromptInputProps) {
   }
 
   function handleFileSelect(path: string) {
+    const isFolder = path.endsWith("/")
     const filename = path.split("/").pop() || path
 
+    if (isFolder) {
+      const currentPrompt = prompt()
+      const pos = atPosition()
+      const cursorPos = textareaRef?.selectionStart || 0
+
+      if (pos !== null) {
+        const before = currentPrompt.substring(0, pos + 1)
+        const after = currentPrompt.substring(cursorPos)
+        const folderPath = path.slice(0, -1)
+        const newPrompt = before + folderPath + after
+        setPrompt(newPrompt)
+        setFileSearchQuery(folderPath)
+
+        setTimeout(() => {
+          if (textareaRef) {
+            const newCursorPos = pos + 1 + folderPath.length
+            textareaRef.setSelectionRange(newCursorPos, newCursorPos)
+            textareaRef.style.height = "auto"
+            textareaRef.style.height = Math.min(textareaRef.scrollHeight, 200) + "px"
+            textareaRef.focus()
+          }
+        }, 0)
+      }
+
+      return
+    }
+
     const existingAttachments = attachments()
     const alreadyAttached = existingAttachments.some((att) => att.source.type === "file" && att.source.path === path)