notes(#454): per-recipient view/edit folder sharing

- Schema: noteFolderShares.permission ('view'|'edit', default 'view').
  Project uses drizzle-kit push (no migration files); existing rows
  pick up the default automatically on next push.
- Server: resolveFolderEditAccess + emitFolderChanged helpers.
  - POST/PATCH/DELETE/checklist now allow folder editors.
  - Editors stamp notes with folder owner's userId; labels validated
    against owner; PATCH editors blocked from unfile (folderId=null)
    and cross-folder moves to non-matching owners.
  - emitFolderChanged fires for owner AND editor mutations across
    create / patch (old + new folder) / delete / checklist toggle.
  - PUT /shares accepts both legacy recipientUserIds and new
    recipients:[{userId,permission}]; diffs add/update/remove/perm-flip.
  - GET /shares, /shared-with-me, /shared-notes return permission /
    myPermission / readOnly.
  - Distinct socket events: note-folder-shared (added),
    note-folder-share-updated (permission flipped),
    note-folder-unshared (removed). Permission events carry the new
    permission so clients can react.
- Client:
  - notes-api types: FolderSharePermission, myPermission on
    SharedFolder/SharedFolderView, permission on FolderShareRecipient,
    readOnly:boolean on SharedFolderNote.
  - useUpdateFolderShares takes recipients[].
  - useCreate/Update/DeleteNote also invalidate ['note-folders'] so
    actor's shared-folder rail badge stays fresh.
  - FolderShareDialog: per-row checkbox + segmented View/Edit toggle.
  - SharedFolderView: editor mode mounts Composer + NoteCard with
    full edit/delete/archive affordances; Send hidden in editor
    context (Composer + NoteCard hideSend prop) since /send is
    owner-only.
  - folders-rail: per-folder permission badge.
  - socket: handlers for shared / share-updated / unshared all
    invalidate the right query keys for live UI flips.
  - Locales: shareDescriptionPerm, permissionView/Edit, canEdit
    (en + ar).
- Tests: new permission roundtrip test in notes-share.test.mjs covering
  view-rejects-write, edit-can-write, editor-cannot-unfile,
  editor-create-stamped-to-owner, downgrade/upgrade flips.
- Pre-existing executive-meetings.ts type errors are out of scope.

artifacts/tx-os/src/hooks/use-notifications-socket.ts

@@ -343,6 +343,19 @@ export function useNotificationsSocket() {
         invalidate(["note-folders"]);
       },
     );
+    // Task #454: dedicated event for permission-only flips on an
+    // existing share (view ↔ edit). Same invalidation as `shared`,
+    // but kept distinct so the contract is explicit and so future UI
+    // can react with a toast like "Your access changed to Edit".
+    socket.on(
+      "note-folder-share-updated",
+      (payload?: { folderId?: number; permission?: "view" | "edit" }) => {
+        invalidate(["note-folders", "shared-with-me"]);
+        if (typeof payload?.folderId === "number") {
+          invalidate(["notes", "shared-folder", payload.folderId]);
+        }
+      },
+    );
     socket.on(
       "note-folder-unshared",
       (payload?: { folderId?: number }) => {