feat: add BVK exchange library

README.md

@@ -0,0 +1,43 @@
+# Mila
+
+Mila is a small Go library for BVK media-complex content exchange.
+
+It implements the HTTP protocol where BVK pushes the currently displayed
+content state to the media complex:
+
+```text
+GET /set-content?route=<R>&str=<S>&tpl_name=<T>
+GET /get-content
+```
+
+The library intentionally does not know anything about snapshots, route
+progress, geolocation, frontend state, or media playback rules. It only parses,
+validates, stores, logs, and returns BVK content state.
+
+## Usage
+
+```go
+store := mila.NewFileStore("/srv/persistence/client_logs/bvk_content.json")
+
+handler := mila.NewHandler(mila.DefaultConfig(), store,
+    mila.WithOnSet(func(state mila.ContentState) {
+        // Application-specific integration goes here.
+    }),
+)
+
+srv := &http.Server{
+    Addr:    "0.0.0.0:13280",
+    Handler: handler,
+}
+```
+
+## State
+
+```json
+{
+  "route": "3",
+  "str": "Гостиный двор - Gostiny dvor",
+  "tpl_name": "Гостиный двор",
+  "updated_at": "2026-07-12T12:00:00Z"
+}
+```