breadsearch: emit bread.search.opened and bread.search.opened_result

Wire the GTK overlay to the bread event fabric via bread-utils
BreadClient (app id search). Fail-silent when breadd is down.
No command verbs — the overlay has no existing command surface.

EVENTS.md

@@ -0,0 +1,36 @@
+# breadsearch — bread event integration
+
+breadsearch is a standalone document-search overlay: it works exactly the
+same with or without `breadd` running. When breadd *is* present, the
+`breadsearch` GTK overlay publishes events into the shared bread automation
+fabric. 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: **`search`**. Transport: `bread-utils`'s `bread_client` module
+(feature `bread-client`) — the overlay links it directly. Each `emit` is
+its own short-lived connection (`BreadClient::emit` is fire-and-forget,
+the same stance as `bread-emit`). breadmill, the indexing daemon, does
+not talk to breadd.
+
+## Events published (`bread.search.*`)
+
+| Event | Data | When |
+|-------|------|------|
+| `bread.search.opened` | `{}` | The overlay window maps (the search panel is shown). |
+| `bread.search.opened_result` | `{ "path": "<hit path>" }` | The user opens a hit — Enter / click opens the file, Ctrl+Enter reveals its folder. `path` is the hit's document path, not the parent folder. |
+
+## Commands honored (`bread.command.search.*`)
+
+None. The overlay is a short-lived toggle process with no existing command
+surface (no show/hide/query IPC beyond the PID-file toggle and breadmill's
+own query socket). Adding verbs would mean inventing a control plane that
+does not exist; if/when breadsearch grows one, the corresponding
+`bread.command.search.*` verbs should be added at the same time, not stubbed
+out ahead of it.
+
+## 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) — breadsearch's
+  overlay and breadmill's indexing/query path are entirely unaffected.