Stage 17 round 6 (#18, PR D): admin Messages moderation section

A new /_gm/messages console page lists posted chat messages (nudges
excluded) newest-first — time, source (guest/robot/oldest identity kind),
sender (linked to the user card), IP, body, game (linked to the game card)
— searchable by sender name / external-id glob masks and pinnable to one
game (?game=) or sender (?user=), linked from the game and user cards.

The list query lives in social (raw SQL, kind='message', source via a SQL
CASE), reusing the now-exported account.LikePattern. Server-rendered
adminconsole MessagesView + messages.gohtml, 50/page via the shared pager.

Tests: adminconsole render case; backend integration AdminListMessages
(real Postgres) — nudge exclusion, game/sender pins, glob masks, source.
Docs: ARCHITECTURE section 8 chat moderation, PLAN round-6.

backend/internal/server/handlers_admin_console.go

@@ -19,6 +19,7 @@ import (
 	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/game"
 	"scrabble/backend/internal/robot"
+	"scrabble/backend/internal/social"
 )
 
 // adminPageSize is the page size of the admin console's paginated lists.
@@ -51,6 +52,7 @@ func (s *Server) registerConsole(router *gin.Engine) {
 	gm.GET("/complaints", s.consoleComplaints)
 	gm.GET("/complaints/:id", s.consoleComplaintDetail)
 	gm.POST("/complaints/:id/resolve", s.consoleResolveComplaint)
+	gm.GET("/messages", s.consoleMessages)
 	gm.GET("/dictionary", s.consoleDictionary)
 	gm.POST("/dictionary/reload", s.consoleReloadDictionary)
 	gm.POST("/dictionary/changes/apply", s.consoleApplyChanges)
@@ -130,6 +132,60 @@ func (s *Server) consoleUsers(c *gin.Context) {
 	s.renderConsole(c, "users", "users", "Users", view)
 }
 
+// consoleMessages renders the paginated chat-message moderation list, optionally pinned to
+// one game (?game=) or sender (?user=) and filtered by sender glob masks (?name / ?ext).
+func (s *Server) consoleMessages(c *gin.Context) {
+	ctx := c.Request.Context()
+	page := consolePage(c)
+	gameID, _ := uuid.Parse(strings.TrimSpace(c.Query("game")))
+	userID, _ := uuid.Parse(strings.TrimSpace(c.Query("user")))
+	filter := social.AdminMessageFilter{
+		GameID:   gameID,
+		SenderID: userID,
+		NameMask: c.Query("name"),
+		ExtMask:  c.Query("ext"),
+	}
+	total, _ := s.social.AdminCountMessages(ctx, filter)
+	items, err := s.social.AdminListMessages(ctx, filter, adminPageSize, (page-1)*adminPageSize)
+	if err != nil {
+		s.consoleError(c, err)
+		return
+	}
+	q := url.Values{}
+	if filter.GameID != uuid.Nil {
+		q.Set("game", filter.GameID.String())
+	}
+	if filter.SenderID != uuid.Nil {
+		q.Set("user", filter.SenderID.String())
+	}
+	if strings.TrimSpace(filter.NameMask) != "" {
+		q.Set("name", filter.NameMask)
+	}
+	if strings.TrimSpace(filter.ExtMask) != "" {
+		q.Set("ext", filter.ExtMask)
+	}
+	view := adminconsole.MessagesView{
+		Pager:       adminconsole.NewPager(page, adminPageSize, total),
+		NameMask:    filter.NameMask,
+		ExtMask:     filter.ExtMask,
+		FilterQuery: q.Encode(),
+	}
+	if filter.GameID != uuid.Nil {
+		view.GameID = filter.GameID.String()
+	}
+	if filter.SenderID != uuid.Nil {
+		view.UserID = filter.SenderID.String()
+	}
+	for _, m := range items {
+		view.Items = append(view.Items, adminconsole.MessageRow{
+			ID: m.ID.String(), SenderID: m.SenderID.String(), SenderName: m.SenderName,
+			Source: m.Source, IP: m.SenderIP, Body: m.Body,
+			GameID: m.GameID.String(), CreatedAt: fmtTime(m.CreatedAt),
+		})
+	}
+	s.renderConsole(c, "messages", "messages", "Messages", view)
+}
+
 // consoleUserDetail renders one account with its stats, identities and games.
 func (s *Server) consoleUserDetail(c *gin.Context) {
 	ctx := c.Request.Context()