Replace the "drop a session token in a file" workflow with a real
Chrome-style email login. The Cloudflare worker already had Better
Auth's `email-otp` plugin wired into `SEND_EMAIL`; this commit
builds the renderer-side counterpart.
Worker side:
- Move the OTP sender from `auth@elydora.com` to `browser@elydora.com`
(wrangler.toml `allowed_sender_addresses` + better_auth.ts
`EMAIL_OTP_FROM_ADDRESS`). Worker must be redeployed to pick this up.
Client side (`ely_sync_client::email_otp`):
- `send_email_otp(config, email)` POSTs `/api/auth/email-otp/send-verification-otp`
with `{ email, type: "sign-in" }`.
- `verify_email_otp(config, email, otp)` POSTs `/api/auth/sign-in/email-otp`,
reads the Better Auth session token from the JSON body's `token` field
with the `Set-Cookie: better-auth.session_token=…` header as the
documented fallback channel, and returns it as a `BearerToken`.
Shell side (`shell/auth.rs` + `shell/internal_pages/sync.rs`):
- New `AuthFlowPhase` (Idle / SendingCode / AwaitingOtp / Verifying /
Error) tracks the in-flight form. Two off-thread workers run the
HTTP exchanges so the GPUI render loop never blocks.
- Successful verify saves the bearer via `SyncEngine::install_bearer`
and triggers an immediate snapshot upload, so the user is signed in
+ initial-synced in one click.
- Sync settings page replaces the bare "Sync now" button row with an
account card: when SignedOut → email field + Send code → OTP field
+ Verify / Resend; when signed in → an account chip + Sign out.
- `trigger_cloud_sync_upload` no longer takes a `Context` param so
the post-auth path can fire it from the inbox-drain pass without
needing a window context.
ZacharyZhang-NY