file browser: the eight defects from the audit

1. Kebab Cut/Copy silently did nothing, and sometimes cut the wrong rows.
   `EllipsisMenu` stops click propagation so opening it does not toggle
   selection — but Cut, Copy, Download, Delete and Compress all act on the
   SELECTION, which meant the kebab operated on whatever was selected elsewhere,
   or returned early with no toast at all. Right-click never had this because it
   selects first. Both now call one `ensureSelected`, on open.

2. Every menu vanished during a search. That branch had no ContextMenu and its
   rows are not FileItems, so right-click fell through to the browser. The folder
   menu is now declared once and mounted in both branches — it acts on
   `currentPath`, which a search does not change, so it stays meaningful.

   Search ROWS get their own three-item menu rather than the row menu: a hit
   carries an absolute path from anywhere in the tree, while every row-menu
   handler builds its path from the folder being browsed. Reusing it would have
   acted on a different file with the same name. `DirEntry.path` is optional —
   only search results carry one — so it is guarded, not asserted.

3. Download and Copy path now fan out over a multi-selection, the rule Delete and
   Compress already used. The menu downloaded one of six selected files while the
   toolbar zipped all six.

   Chat is deliberately NOT included: `chatContext` is a single path that the
   provider string-splits into a working directory, so a list would need Chat's
   contract changed. Left alone rather than half-done.

4. Read Aloud stopped offering TTS on binaries — same guard the editor got, since
   `text` is `getFileType`'s fallback and caught .exe and .sqlite.

5. `POST /file-browser/download` is filed as a read. It zips a selection and
   writes nothing; it is a POST only because a list of paths does not fit a query
   string. A read-level member could download a whole folder but not two files.
   Proved by hand that `readOnlyWrites: ['/download']` permits GET and POST
   /download, and still denies /download-video, /rm and /write — `isPrefixOf` is
   segment-aware, so the sibling route does not leak.

6. `disabled` had no use anywhere in the feature — the shared item type did not
   even expose it. It does now, and the first real case: `/file-browser/read`
   refuses over 5 MB, so Open in editor on a 40 MB log opened an editor that then
   failed. Hiding it would have suggested the file is not text; disabled says the
   true thing.

7. The grid kebab could fade out while its own dropdown was open — list view had
   `data-[state=open]:opacity-100` and grid did not.

8. Dead exports `getMatchingTasks` / `getMatchingAgents` removed. Both were the
   ungrouped input to the grouped form the menu actually renders; exporting them
   invited a second code path that never arrived.

9 is untouched on purpose — a plugin cannot register a menu item, and the music
plugin is where that should be designed.

tsgo clean, frontend builds, 808 pass / 7 fail unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/servers/permissions/registry.ts

@@ -311,6 +311,13 @@ const CORE_REGISTRY: Permission[] = [
     kind: 'confined',
     api: ['/file-browser', '/upload'],
     routes: ['/files', '/code-editor'],
+    // `POST /file-browser/download` zips a multi-selection and streams it back. It writes nothing — it is
+    // a POST only because a list of paths does not fit a query string. Without this a read-level member
+    // could download a whole folder (GET /download) but not two files, which is not a rule anyone chose.
+    //
+    // `isPrefixOf` is segment-aware, so this does NOT also permit `/download-video` — which really is a
+    // write, fetching a video onto the disk.
+    readOnlyWrites: ['/download'],
   },
   {
     key: 'tasks',