Emit bread.help.opened when the main window is shown

Fail-silent via bread-utils BreadClient (ecosystem v0.7.1, bread-client).
No command verbs. Silent autostart and screenshot mode do not emit.

EVENTS.md

@@ -0,0 +1,42 @@
+# breadhelp — bread event integration
+
+breadhelp is a standalone GTK help center: it works exactly the same with
+or without `breadd` running. When breadd *is* present, it publishes one
+event after the main window is actually shown. See the parent `bread`
+repo's `Documentation.md` — specifically its "Namespaces" and
+"Integrating a bread\* app" sections — for the general convention this
+follows.
+
+App id: **`help`**. Transport: `bread-utils`'s `bread_client` module
+(feature `bread-client`) — breadhelp links it directly. Each `emit` is
+its own short-lived connection. There is no long-running command
+subscription.
+
+## Events published (`bread.help.*`)
+
+| Event | Data | When |
+|-------|------|------|
+| `bread.help.opened` | `{ "autostart": bool }` | The main help window is presented (`ApplicationWindow::present`). `autostart` is `true` when that invocation was launched with `--autostart`. |
+
+Not emitted when:
+
+- every-login `--autostart` builds a hidden window because onboarding is
+  already done (silent autostart)
+- first-run `--autostart` starts the tour overlay without presenting the
+  main window
+- `--onboard` / `--tour-event` (tour only)
+- `--screenshot` (capture, not a user-visible open)
+
+## Commands honored (`bread.command.help.*`)
+
+None. Opening the help center, starting the tour, and applying one-click
+fixes already exist as local CLI / UI paths. There is no command
+subscription, and no verb is stubbed as a no-op. If breadhelp later grows
+a bus verb that maps to real behavior, add it then.
+
+## Fail-safe behavior
+
+- If breadd isn't installed or isn't running, `emit` is a silent no-op
+  (`BreadClient::emit` never blocks or errors the caller) — the help
+  center, tour, and screenshots are entirely unaffected.
+- There is no command subscription to reconnect.