0.2.42: external Administrator role with entity-scoped management

The external fund_administrator role (relabeled Administrator) now signs
into the full admin interface, fenced to the funds and SPVs granted to
it via EntityAccess:

- Partners, capital accounts, documents (upload and delete), entity
  edits, and eNAV imports for its own funds only; no fund creation,
  valuation sign-off, audit log, or investor view.
- Scoped user management: sees and manages only investors tied to its
  funds; creates investor accounts only; updates preserve grants on
  funds outside its scope.
- New DELETE /api/users/{id} (in-app Delete user button) with the
  cascade cleanup factored out of the CLI; Service Admin and self are
  protected, and an Administrator can only delete an investor who
  belongs solely to its funds.
- Internal fund_admin relabeled 'Staff (all funds)' and dropped from
  the create picker to end the two-similar-names confusion.
- Version badge removed from the UI (sidebar and portal header); the
  build version now logs to the browser console instead.
- deploy/.startos (signing key) added to .gitignore.

frontend/src/version.ts

@@ -1,4 +1,4 @@
 // Bumped each release so the running build is visible in the UI.
 // If the number shown in the app doesn't match the installed s9pk version,
 // the new frontend isn't actually being served.
-export const APP_VERSION = "0.2.40";
+export const APP_VERSION = "0.2.42";