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.

docs/FUNCTIONAL.md

@@ -346,8 +346,9 @@ over-grant cannot be reversed there.
 The console works a **feedback** queue too (`/_gm/feedback`): the messages players sent, filtered
 **unread / read / archived** with per-user search, each shown with its sender, source, channel
 (with the bot language — en/ru — for a Telegram message), the sender's interface
-language, the **app version** it was sent from, IP, the filed time (in UTC and the sender's time
-zone) and any attachment. The operator can mark a message read, **reply** to the player (delivered
+language, the **app version** it was sent from, IP, the filed time (in three zones — UTC, the
+browser zone detected at submit, and the sender's saved zone, each shown `N/A` when not known) and
+any attachment. The operator can mark a message read, **reply** to the player (delivered
 in-app), archive it, delete it, or delete every message from that player — and, alongside a delete,
 **bar the player from feedback** (a `feedback_banned` role, distinct from a full account block: it
 stops only feedback submission). Roles are listed and granted/revoked on the user card. Opening a