fix(plugins): file events are objects, deletion is a typed error, DocumentFrame owns its fallback

- watch listeners receive { type: "changed" } | { type: "deleted" }, so later
  versions can add fields without breaking them.
- PluginFileDeletedError joins PluginFileConflictError. The read hooks report a
  deleted file with it, and a write over a deleted file rejects with it; Source
  shows that as the deleted notice. PluginFileConflictError now means only
  "changed on disk".
- DocumentFrame on Android shows Paseo's "<TYPE> files can't be shown on this
  device" message for documents its WebView cannot display, so the PDF example
  is useFileUrl + Loading + DocumentFrame with no platform branch.

plugin-examples/pdf-panel/README.md

@@ -4,8 +4,8 @@ Requires Paseo 0.13.0 or later. Install this directory with
 `paseo plugin install /absolute/path/to/plugin-examples/pdf-panel`, then open a `.pdf` in Files.
 
 The panel resolves the file's local URL with `useFileUrl`, shows `Loading` until it does, and passes
-it to `DocumentFrame` on web and iOS. Android shows the filename, size, and a message that inline
-PDF rendering is unavailable. The plugin does not construct daemon URLs.
+it to `DocumentFrame`. Where a platform cannot show a PDF inline (Android), `DocumentFrame` says so.
+The plugin does not construct daemon URLs.
 
 See the [file panel reference](https://paseo.sh/docs/plugins/reference#file-panels).
 

plugin-examples/pdf-panel/client/pdf-panel.tsx

@@ -10,12 +10,7 @@ const messageStyle = {
   padding: 24,
 } as const;
 
-export function PdfPanel(props: PluginFilePanelProps) {
-  if (props.layout.platform === "android") return <AndroidPdf {...props} />;
-  return <InlinePdf {...props} />;
-}
-
-function InlinePdf({ file, theme }: PluginFilePanelProps) {
+export function PdfPanel({ file, theme }: PluginFilePanelProps) {
   const url = useFileUrl(file);
   const textStyle = useMemo(() => ({ color: theme.colors.statusDanger }), [theme]);
   if (url.status === "loading") return <Loading />;
@@ -28,14 +23,3 @@ function InlinePdf({ file, theme }: PluginFilePanelProps) {
   }
   return <DocumentFrame url={url.url} testID="pdf-panel" />;
 }
-
-function AndroidPdf({ file, theme }: PluginFilePanelProps) {
-  const textStyle = useMemo(() => ({ color: theme.colors.foregroundMuted }), [theme]);
-  return (
-    <View style={messageStyle}>
-      <Text style={textStyle}>
-        {file.name} ({Math.round(file.size / 1024)} KB). Android cannot render PDF inline.
-      </Text>
-    </View>
-  );
-}