fix(build): add --standalone flag to embed real frontend in iOS builds
build-ios.sh always replaced dist/index.html with a bootstrap redirect
to the HMR dev server. The e2e test built with this script but never ran
a dev server, so the webview loaded a dead redirect — no frontend, no
IPC commands, and ensure_database_initialized() was never called. This
caused Phase 3 dedup to silently never run.
Add --standalone flag that skips the bootstrap replacement and embeds the
real bundled frontend. The e2e test now uses --standalone so the app
loads its actual UI, invokes Rust IPC commands naturally, and DB
initialization (including dedup migration) happens via the normal lazy
path.
Reverts the eager DB init from d3f23354 — lazy init on first DB access
is the correct design since the Share Extension also needs it.