feat(feedback): capture the browser UTC offset; Filed time in three zones

The account time zone defaults to UTC until a player saves a profile, so a
report's Filed time could only render in UTC even for a player clearly in
another zone. Capture the client's detected "±HH:MM" offset (browser_tz) with
each submission and show the Filed time in three zones in the operator console
— UTC, the browser offset detected at submit, and the sender's saved profile
zone — each shown "N/A" when not known, so the operator can tell what is
certainly known from what is merely defaulted.

- Thread browser_tz through the fbs envelope (+ Go/TS codegen), the gateway
  transcode + backend client, and the backend feedback service/store; add the
  column via migration 00004 (additive, image-rollback-safe).
- Fix fmtTimeIn to resolve "±HH:MM" offsets via account.ResolveZone;
  time.LoadLocation alone silently fell back to UTC for offset zones, which is
  the second reason a "+02:00" sender showed only UTC.
- Update ARCHITECTURE/FUNCTIONAL(+ru) docs and the feedback integration test.

ui/src/lib/transport.ts

@@ -10,6 +10,7 @@ import { createConnectTransport } from '@connectrpc/connect-web';
 import { Gateway } from '../gen/edge/v1/edge_pb';
 import { GatewayError, type GatewayClient } from './client';
 import * as codec from './codec';
+import { browserOffset } from './profileValidation';
 import { registerProbe, reportOffline, reportOnline } from './connection.svelte';
 import { backoffMs, isConnectionCode, retryable, toGatewayError } from './retry';
 
@@ -147,9 +148,10 @@ export function createTransport(baseUrl: string): GatewayClient {
       await exec('chat.read', codec.encodeGameAction(id));
     },
     async feedbackSubmit(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__));
+      // The app build (Vite define) and the device's detected UTC offset ride with the report
+      // so the operator sees which version it came from and the local time it was filed; the
+      // caller need not pass them.
+      await exec('feedback.submit', codec.encodeFeedbackSubmit(body, attachment, attachmentName, channel, __APP_VERSION__, browserOffset()));
     },
     async feedbackGet() {
       return codec.decodeFeedbackState(await exec('feedback.get', codec.empty()));