feat(oxibadge): add month-confirmation flow and fetch records/employees

Adds the screen after onboarding: pick a month/year (ConfirmMonth), show
loading screens while the device is queried, then download that month's
records and resolve each distinct employee's name, printing both to
stdout (debug pretty-print) before landing on the placeholder "done"
screen.

- r701: RecordIterator's boxed stream is now Send, required for it to
  cross into a Tauri command's future.
- oxibadge: load_records/load_employees commands, sharing the existing
  3-retry connect_with_retries helper. load_records uses skip_while/
  take_while on the device's newest-first stream to grab only the
  target month without walking its whole history, then a single
  collect + in-place Vec::reverse() back to chronological order.
- Shared LoadingScreen/Intro components extracted so future screens
  reuse the same look without duplicating markup/CSS.

Assisted-by: Claude Sonnet 5 <noreply@anthropic.com>

oxibadge/src-tauri/Cargo.toml

@@ -19,4 +19,6 @@ tauri-build = { version = "2", features = [] }
 tauri = { version = "2", features = [] }
 serde = { version = "1", features = ["derive"] }
 toml = "0.9"
-r701 = { path = "../../r701" }
+r701 = { path = "../../r701", features = ["serde"] }
+chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
+tokio-stream = { version = "0.1.19", default-features = false }