Channel Store: No SELECT * (#32167)

* Replace SELECT * with explicit column lists in channel store

Migrates channel_store.go away from SELECT * patterns to explicit column
lists for better performance, maintainability, and schema safety.

- Replace GetPinnedPosts raw SQL with query builder using postSliceColumns()
- Replace "cc.*" in group channel search with channelSliceColumns()
- Replace GetChannelsBatchForIndexing raw SQL with query builder
- Replace channel member and team queries with respective column helpers
- Use SelectBuilder helper instead of manual ToSql() calls

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Replace SELECT * with COUNT(*) in user_test.go

Replaces unnecessary SELECT * queries with SELECT COUNT(*) in
TestPermanentDeleteUser bot count verification. Only needs to check
the count of bots, not retrieve full bot records.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>

server/channels/store/storetest/channel_store.go

@@ -7076,7 +7076,7 @@ func testChannelStoreSearchGroupChannels(t *testing.T, rctx request.CTX, ss stor
 	require.NoError(t, nErr)
 
 	for _, userID := range userIds {
-		_, err := ss.Channel().SaveMember(rctx, &model.ChannelMember{
+		_, err = ss.Channel().SaveMember(rctx, &model.ChannelMember{
 			ChannelId:   gc2.Id,
 			UserId:      userID,
 			NotifyProps: model.GetDefaultChannelNotifyProps(),
@@ -7092,6 +7092,20 @@ func testChannelStoreSearchGroupChannels(t *testing.T, rctx request.CTX, ss stor
 	_, nErr = ss.Channel().Save(rctx, &gc3, -1)
 	require.NoError(t, nErr)
 
+	// Make gc3 policy enforced
+	_, err = ss.AccessControlPolicy().Save(rctx, &model.AccessControlPolicy{
+		ID:      gc3.Id,
+		Version: model.AccessControlPolicyVersionV0_1,
+		Type:    model.AccessControlPolicyTypeChannel,
+		Rules: []model.AccessControlPolicyRule{
+			{
+				Actions:    []string{},
+				Expression: "",
+			},
+		},
+	})
+	require.NoError(t, err)
+
 	for _, userID := range userIds {
 		_, err := ss.Channel().SaveMember(rctx, &model.ChannelMember{
 			ChannelId:   gc3.Id,
@@ -7108,6 +7122,16 @@ func testChannelStoreSearchGroupChannels(t *testing.T, rctx request.CTX, ss stor
 		}
 	}()
 
+	// assertChannelListPopulated verifies that the channel objects in the given channel list
+	// are fully populated.
+	assertChannelListPopulated := func(t *testing.T, channelList model.ChannelList) {
+		for _, actualChannel := range channelList {
+			expectedChannel, err := ss.Channel().Get(actualChannel.Id, false)
+			require.NoError(t, err)
+			assert.Equal(t, expectedChannel, actualChannel, "channel %q in channel list missing metadata", actualChannel.Id)
+		}
+	}
+
 	testCases := []struct {
 		Name           string
 		UserID         string
@@ -7169,6 +7193,7 @@ func testChannelStoreSearchGroupChannels(t *testing.T, rctx request.CTX, ss stor
 			}
 
 			require.ElementsMatch(t, tc.ExpectedResult, resultIds)
+			assertChannelListPopulated(t, result)
 		})
 	}
 }