ExtensionNode string params always open folder picker, ignoring pickerIntent: image #155

Bug

ExtensionNode always opens a folder picker for params with type: "string", ignoring the pickerIntent field that extension manifests use to request an image file picker.

Repro

Any extension manifest with a param like:

{
  "id": "front_image_path",
  "type": "string",
  "pickerIntent": "image",
  "filters": [{ "name": "Images", "extensions": ["png", "jpg", "jpeg", "webp"] }]
}

renders a text input with a folder-icon button. Clicking the button opens selectDirectory() regardless of pickerIntent or filters.

Source

src/areas/workflows/nodes/ExtensionNode.tsx lines 91-108:

if (param.type === "string") {
  return (
    <div className="flex items-center gap-1">
      <input ... />
      <button onClick={async () => {
        const p = await window.electron.fs.selectDirectory()
        if (p) onChange(p)
      }}>...</button>
    </div>
  )
}

The handler unconditionally calls selectDirectory(). There is no branch that consults param.pickerIntent.

Suggested fix

Honor pickerIntent: "image" (and other intents) by routing to an image picker. An image dialog already exists at electron/main/ipc-handlers.ts:197 (filters: [{ name: "Images", extensions: ["jpg","jpeg","png","webp"] }], properties: ["openFile"]).

const handler =
  param.pickerIntent === "image"
    ? window.electron.fs.selectImage   // expose the existing image dialog via preload
    : window.electron.fs.selectDirectory

<button onClick={async () => { const p = await handler(); if (p) onChange(p) }}>
  {param.pickerIntent === "image" ? <ImageIcon/> : <FolderIcon/>}
</button>

Impact

Affects every model/process extension that wants a file path param for an image (e.g. multi-view shape-gen extensions where the front/back/side images need explicit file paths). Without the fix, users must paste paths manually or rely on plugin-side workarounds (e.g. "if user picked a folder, scan for first image inside") -- both poor UX.

Happy to submit a PR if the direction looks right.