Show live values on the mockup, blink a screen to identify it, try an alert, copy and share layouts (0.2.74)

The tiles draw what Home Assistant reports (a new /api/states answers for the tiles on the page); the ···
menu gets Identify (the screen's own show_alert with flash), Copy layout from another screen, Export and
Import as JSON; the Alerts page opens with Try it (/api/alerts/test, one screen or all); the library filters
by room and hides what is placed, with lit icons for what is on; ⌘K searches screens, entities and actions;
the Update badge lists what's new from the changelog (copied into the image) and a running update shows a
progress bar with the ESPHome stage and the last log line.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

screen_manager/CHANGELOG.md

@@ -7,6 +7,12 @@ A new editor, built as a Vue app, with the same firmware.
 - **Pages side by side.** The pages of a screen stand next to each other, at the screen's own shape (square for a Guition, 4:3 for a CYD), the way you swipe through them. Dragging from the library onto a page and between cells works as before, with mouse and touch; drop past the last page for a new one.
 - **The top bar is part of the mockup.** Tap the bar on any page to name the screen and choose its items; the drawer shows every item as the screen draws it. Adding the time, the date, the dial or an entity happens in the same drawer.
 - **Screen settings as a tab** next to Layout, with the same rows as the settings page on the screen. **Read current data** and **Override YAML** live in the ··· menu of the screen; New screen, Firmware & USB, Alerts and the app Settings are pages of their own, reached from the sidebar.
+- **Live values on the mockup.** The tiles show what Home Assistant reports right now: the temperature with its unit, On or Off with a lit icon, the heating's current temperature and setpoint, the volume, a cover's position, the song that plays. Sliders and switches on the cards stand where they stand on the screen. The page asks every eight seconds while it is open.
+- **Identify.** The ··· menu of a screen has Identify: the screen shows a short card and blinks its backlight, so with three screens you know which is which. Needs firmware 0.2.31 or newer, like every alert.
+- **Try an alert.** The Alerts page opens with Try it: fill in the same seven fields an automation sends, choose one screen or all of them, and Send. The result says how many screens showed it and which fields were left empty.
+- **Copy, export, import.** The ··· menu copies the layout of another screen onto this one, exports the layout as a JSON file (and to the clipboard), and imports one. An imported layout is trimmed to what the screen's firmware holds, and nothing is sent before you press Save & send.
+- **A smarter library.** A room filter and Hide placed next to the domain chips; a lit icon for a light, switch or fan that is on, a grey one for an entity Home Assistant can't reach. ⌘K (Ctrl+K) opens a search over screens, entities and actions: open a screen, add an entity to the page you have open, save, identify, export.
+- **Updates with content.** The Update badge has What's new: the changelog lines since that screen's firmware. A running update shows a progress bar with its stage (building, writing over Wi-Fi, waiting for the screen, checking it stays up) and the last line of the ESPHome log; Settings → Firmware updates shows the log's tail.
 - **Dark mode follows your browser**, as Home Assistant's own Auto theme does.
 - Same add-on API, same data, same firmware: nothing to update on the screens. The page is now built with Vue and Vite (`web/`); its files carry a hash of their content, so an update never runs an old script against a new page.