LIVE https://todo-swift.bfj.oncarlos.com 354c88a

## Checked

- `make test`: 21 Swift Testing tests pass.
- Shared suite against `dist/app --listen 127.0.0.1:<port>`: 67 passed,
  3 skipped (the suite's own skips: blur and Escape need JavaScript, and
  the screenshot is compared with JavaScript on only).
- `scripts/boot-check.sh dist/app-linux-arm64`: `/healthz` and
  `/api/version` 200 (`354c88a`), clean exit on SIGTERM.
- `make deploy`: shipped and promoted `354c88a` to `edge`, and
  `/api/version` on the live host reports it.
- Shared suite against `https://todo-swift.bfj.oncarlos.com`: 67 passed,
  3 skipped.

## Notes

- Stack: Hummingbird 2 and SQLiteNIO (which compiles SQLite 3.54 in),
  built with the Swift 6.2 Static Linux SDK. The arm64 binary is static,
  stripped, and 22 MB. Turning off Hummingbird's `FullFoundation` trait
  and importing only `FoundationEssentials` took it down from 66 MB.
- A cold `make build-arm64` takes a few minutes here; an incremental one
  after `make bump` recompiles one file.
- Nothing in the contract needed a deviation.

## Review round

Both findings are fixed in `static/app.js` (commit `354c88a`):

1. **Typing during an add.** The form is read and the new-todo input
   cleared when the form is submitted, not when the answer arrives. A
   second Enter while the first add is still pending is queued, not
   dropped. Each edit is saved once, guarded per item, instead of
   blocking the whole form.
2. **Stale snapshots.** Actions go through one promise queue, so they
   reach the server and come back in the order they were made, and the
   last swap is always the newest state.

Checked by hand in Chromium with Playwright, with the first response held
back 800 ms. Adding "first", then "second", then typing "third" left both
items saved and "third" still in the input. Toggling two items quickly
left both completed, with "0 items left". The shared suite passes
locally (67 passed, 3 skipped) and against the live host (67 passed,
3 skipped).

The first `make deploy` was refused with "too many uploads" (a
platform-side rate limit). My retry loop then shipped the same
`354c88a` build several more times, which was harmless.