feat(feedback): snapshot the sender's language and connector bot at submit

Store the sender's interface language (lang) and, for a message that arrived
through an external connector (Telegram), the bot language (channel_lang) on the
feedback row at submit time, so the operator console shows the state as it was
rather than the account's current settings (same snapshot discipline as a
suspension reason). Added additively in migration 00005. The console detail reads
these columns instead of loading the account live.

backend/internal/postgres/jet/backend/model/feedback_messages.go

@@ -20,6 +20,8 @@ type FeedbackMessages struct {
 	AttachmentName *string
 	SenderIP       *string
 	Channel        string
+	Lang           *string
+	ChannelLang    *string
 	ReadAt         *time.Time
 	ArchivedAt     *time.Time
 	ReplyBody      *string

backend/internal/postgres/jet/backend/table/feedback_messages.go

@@ -24,6 +24,8 @@ type feedbackMessagesTable struct {
 	AttachmentName postgres.ColumnString
 	SenderIP       postgres.ColumnString
 	Channel        postgres.ColumnString
+	Lang           postgres.ColumnString
+	ChannelLang    postgres.ColumnString
 	ReadAt         postgres.ColumnTimestampz
 	ArchivedAt     postgres.ColumnTimestampz
 	ReplyBody      postgres.ColumnString
@@ -78,14 +80,16 @@ func newFeedbackMessagesTableImpl(schemaName, tableName, alias string) feedbackM
 		AttachmentNameColumn = postgres.StringColumn("attachment_name")
 		SenderIPColumn       = postgres.StringColumn("sender_ip")
 		ChannelColumn        = postgres.StringColumn("channel")
+		LangColumn           = postgres.StringColumn("lang")
+		ChannelLangColumn    = postgres.StringColumn("channel_lang")
 		ReadAtColumn         = postgres.TimestampzColumn("read_at")
 		ArchivedAtColumn     = postgres.TimestampzColumn("archived_at")
 		ReplyBodyColumn      = postgres.StringColumn("reply_body")
 		RepliedAtColumn      = postgres.TimestampzColumn("replied_at")
 		ReplyReadAtColumn    = postgres.TimestampzColumn("reply_read_at")
 		CreatedAtColumn      = postgres.TimestampzColumn("created_at")
-		allColumns           = postgres.ColumnList{MessageIDColumn, AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn}
-		mutableColumns       = postgres.ColumnList{AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn}
+		allColumns           = postgres.ColumnList{MessageIDColumn, AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, LangColumn, ChannelLangColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn}
+		mutableColumns       = postgres.ColumnList{AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, LangColumn, ChannelLangColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn}
 		defaultColumns       = postgres.ColumnList{CreatedAtColumn}
 	)
 
@@ -100,6 +104,8 @@ func newFeedbackMessagesTableImpl(schemaName, tableName, alias string) feedbackM
 		AttachmentName: AttachmentNameColumn,
 		SenderIP:       SenderIPColumn,
 		Channel:        ChannelColumn,
+		Lang:           LangColumn,
+		ChannelLang:    ChannelLangColumn,
 		ReadAt:         ReadAtColumn,
 		ArchivedAt:     ArchivedAtColumn,
 		ReplyBody:      ReplyBodyColumn,

backend/internal/postgres/migrations/00004_feedback.sql

@@ -15,7 +15,8 @@ SET search_path = backend, pg_catalog;
 -- attachment is the raw bytes (capped at 1,000,000 in Go); attachment_name carries the original
 -- file name (its extension drives the safe content-type at serve time). sender_ip is the
 -- gateway-forwarded client IP (validated, like chat); channel is the submitting platform
--- (telegram/ios/android/web, validated in Go).
+-- (telegram/ios/android/web, validated in Go). The sender's interface/bot language snapshots
+-- (lang, channel_lang) are added additively in 00005.
 CREATE TABLE feedback_messages (
     message_id      uuid        PRIMARY KEY,
     account_id      uuid        NOT NULL REFERENCES accounts (account_id) ON DELETE CASCADE,

backend/internal/postgres/migrations/00005_feedback_languages.sql

@@ -0,0 +1,15 @@
+-- +goose Up
+-- Snapshot the sender's languages on each feedback message, taken at submit time so the
+-- operator console shows the state as it was, not the account's current settings (the same
+-- snapshot discipline as a suspension's reason). lang is the sender's interface language;
+-- channel_lang is the connector bot language (en/ru) when the message arrived through an
+-- external connector (Telegram), else NULL. Additive over 00004 so it applies forward-safe.
+SET search_path = backend, pg_catalog;
+
+ALTER TABLE feedback_messages ADD COLUMN lang text;
+ALTER TABLE feedback_messages ADD COLUMN channel_lang text;
+
+-- +goose Down
+SET search_path = backend, pg_catalog;
+ALTER TABLE feedback_messages DROP COLUMN IF EXISTS channel_lang;
+ALTER TABLE feedback_messages DROP COLUMN IF EXISTS lang;