feat(feedback): capture the app version; show version + local Filed time

Each feedback submission now carries the client app version (__APP_VERSION__),
snapshotted like the interface language: FlatBuffers FeedbackSubmitRequest gains
a version field → gateway transcode → backend, persisted in a new nullable
feedback_messages.app_version column (migration 00003, additive so an image
rollback stays DB-safe). The operator console detail shows the app version and
renders the Filed time in UTC plus the sender's time zone (fmtTimeIn).

Touches: fbs schema + regenerated Go/TS codegen, codec + transport (the client
attaches its build), gateway transcode + backendclient, feedback store/service,
admin view + template, docs (ARCHITECTURE §15, FUNCTIONAL + _ru). Verified:
feedback integration tests (migration + version round-trip), codec round-trip,
check/unit/build green.

ui/src/lib/transport.ts

@@ -147,7 +147,9 @@ export function createTransport(baseUrl: string): GatewayClient {
       await exec('chat.read', codec.encodeGameAction(id));
     },
     async feedbackSubmit(body, attachment, attachmentName, channel) {
-      await exec('feedback.submit', codec.encodeFeedbackSubmit(body, attachment, attachmentName, channel));
+      // The app build (Vite define) rides with the report so the operator sees which version
+      // it came from; the caller need not pass it.
+      await exec('feedback.submit', codec.encodeFeedbackSubmit(body, attachment, attachmentName, channel, __APP_VERSION__));
     },
     async feedbackGet() {
       return codec.decodeFeedbackState(await exec('feedback.get', codec.empty()));