diff --git a/cmd/ggcode/root.go b/cmd/ggcode/root.go
index 4dbf7216f..b3b2d7f9c 100644
--- a/cmd/ggcode/root.go
+++ b/cmd/ggcode/root.go
@@ -525,10 +525,15 @@ func run(cfg *config.Config, cfgFile, resumeID string, bypass bool) error {
 	projectAutoMem := core.ProjectAutoMem
 	saveMemoryTool := core.SaveMemoryTool
 	startupAssets := core.StartupAssets
-	// Startup notices (sa-45): merge MCP gate/merge warnings with
-	// sleep-time consolidation findings and hand the combined list to the
-	// TUI so they render as system messages on the first frame.
-	startupNotices := append(core.StartupNotices, startupAssets.ConsolidationFindings...)
+	// Startup notices (sa-45): MCP gate/merge warnings render as system
+	// messages on the first frame. Sleep-time consolidation findings are
+	// deliberately NOT appended anymore: they are agent-facing advisory
+	// (already injected into the system prompt via RepairSuggestions,
+	// agentruntime/prompt.go) - showing them in the TUI only surfaced
+	// regex-level false positives (broken-path heuristics on tool names /
+	// cross-project paths) as user-visible noise. User stays in the loop
+	// when the agent acts on a suggestion (save_memory/delete_memory).
+	startupNotices := core.StartupNotices
 	autoFiles := startupAssets.AutoFiles
 	commandMgr := startupAssets.CommandManager
 	trace.Mark("build interactive runtime core")
diff --git a/internal/im/mattermost_adapter.go b/internal/im/mattermost_adapter.go
index 005c4f369..05db846ee 100644
--- a/internal/im/mattermost_adapter.go
+++ b/internal/im/mattermost_adapter.go
@@ -11,7 +11,6 @@ import (
 	"net/http"
 	"net/textproto"
 	"os"
-	"regexp"
 	"strings"
 	"sync"
 	"time"
@@ -404,6 +403,9 @@ func (a *mattermostAdapter) handleWSEvent(ctx context.Context, event map[string]
 		if !isFree && a.requireMention {
 			hasMention := a.hasMention(messageText)
 			if !hasMention {
+				// #4322: previously this drop was silent, making trailing "-"/"."
+				// usernames undiagnosable; keep a debug trace for the rest.
+				debug.Log("mattermost", "adapter=%s channel %s message without mention dropped", a.name, channelID)
 				return
 			}
 			messageText = a.stripMention(messageText)
@@ -467,15 +469,72 @@ func (a *mattermostAdapter) handleWSEvent(ctx context.Context, event map[string]
 	}
 }
 
+// mattermostUsernameContChars are the characters that may legally continue
+// a Mattermost username after a prefix (#4322): server charset is
+// ^[a-z0-9.\-_]+$ (mattermost/server validUsernameChars), so if the byte
+// following a candidate match is one of these, the match is a strict PREFIX
+// of a longer username and must not count.
+const mattermostUsernameContChars = "abcdefghijklmnopqrstuvwxyz0123456789._-"
+
+// mattermostIsUsernameContByte reports whether b may continue a username.
+func mattermostIsUsernameContByte(b byte) bool {
+	return strings.IndexByte(mattermostUsernameContChars, b) >= 0
+}
+
+// mentionsMattermostHandle reports whether text contains "@handle" NOT
+// followed by a legal username continuation character. RE2's \b is an
+// ASCII word boundary that can never match when the handle ends with "-"
+// or "." (legal username endings like "dev-", "ops1."), so the boundary is
+// a post-match check instead (#4322, same fix shape as Matrix #2749).
+// The short-name guard from #963 is preserved: "al" does not match "@alex"
+// because "e" is a continuation byte.
+func mentionsMattermostHandle(lower, handle string) bool {
+	needle := "@" + strings.ToLower(handle)
+	for start := 0; ; {
+		i := strings.Index(lower[start:], needle)
+		if i < 0 {
+			return false
+		}
+		at := start + i
+		end := at + len(needle)
+		if end >= len(lower) || !mattermostIsUsernameContByte(lower[end]) {
+			return true
+		}
+		start = at + 1
+	}
+}
+
+// stripMattermostHandle removes "@handle" occurrences that are not
+// prefixes of a longer username (same boundary rule as
+// mentionsMattermostHandle). Case-insensitive matching happens in the
+// ORIGINAL text's coordinate system via the package-wide ASCII fold
+// (#3572 lesson: never locate in ToLower and consume in the original).
+func stripMattermostHandle(text, handle string) string {
+	needle := "@" + strings.ToLower(handle)
+	var b strings.Builder
+	for i := 0; i < len(text); {
+		if n, ok := matrixASCIIFoldPrefix(text[i:], needle); ok {
+			end := i + n
+			if end >= len(text) || !mattermostIsUsernameContByte(text[end]) {
+				i = end // skip the mention
+				continue
+			}
+		}
+		b.WriteByte(text[i])
+		i++
+	}
+	return b.String()
+}
+
 func (a *mattermostAdapter) hasMention(text string) bool {
 	lower := strings.ToLower(text)
-	// Word-boundary match: bot name "al" must not fire on "@alex" (#963).
+	// Username-boundary match: bot name "al" must not fire on "@alex"
+	// (#963), while trailing "-"/"." usernames still match (#4322).
 	for _, id := range []string{a.botUsername, a.botUserID} {
 		if id == "" {
 			continue
 		}
-		re := regexp.MustCompile(`(?i)@` + regexp.QuoteMeta(id) + `\b`)
-		if re.MatchString(lower) {
+		if mentionsMattermostHandle(lower, id) {
 			return true
 		}
 	}
@@ -483,14 +542,14 @@ func (a *mattermostAdapter) hasMention(text string) bool {
 }
 
 func (a *mattermostAdapter) stripMention(text string) string {
-	// Strip @bot_username and @bot_user_id mentions, with word boundary so a
-	// short bot name ("al") doesn't carve text out of "@alex" (#963).
-	for _, pattern := range []string{a.botUsername, a.botUserID} {
-		if pattern == "" {
+	// Strip @bot_username and @bot_user_id mentions, with a username
+	// boundary so a short bot name ("al") doesn't carve text out of
+	// "@alex" (#963) while non-word endings "\b" missed still strip (#4322).
+	for _, handle := range []string{a.botUsername, a.botUserID} {
+		if handle == "" {
 			continue
 		}
-		re := regexp.MustCompile(`(?i)@` + regexp.QuoteMeta(pattern) + `\b`)
-		text = re.ReplaceAllString(text, "")
+		text = stripMattermostHandle(text, handle)
 	}
 	return strings.TrimSpace(text)
 }
diff --git a/internal/im/zz_issue4322_mattermost_mention_test.go b/internal/im/zz_issue4322_mattermost_mention_test.go
new file mode 100644
index 000000000..a1a62acc7
--- /dev/null
+++ b/internal/im/zz_issue4322_mattermost_mention_test.go
@@ -0,0 +1,81 @@
+package im
+
+import "testing"
+
+// #4322: RE2's \b never matches after a username ending in "-" or "." (both
+// legal per Mattermost's ^[a-z0-9.\-_]+$ charset), so hasMention/stripMention
+// silently dropped those mentions. These tests pin the post-match boundary
+// fix and the #963 short-name guard it must preserve.
+
+func TestIssue4322HasMentionTrailingDashOrDot(t *testing.T) {
+	a := &mattermostAdapter{botUsername: "dev-", botUserID: "abc123"}
+
+	cases := []struct {
+		name string
+		text string
+		want bool
+	}{
+		{"trailing dash username", "@dev- 帮我看下日志", true},
+		{"trailing dash at end of text", "@dev-", true},
+		{"uppercase mention", "@DEV- x", true},
+		{"trailing dot is not our bot", "@ops1. hello", false}, // "ops1." bot covered below
+		{"user id mention", "@abc123 ping", true},
+		{"embedded not a mention", "email dev@example.com", false},
+		{"plain text", "hello world", false},
+	}
+
+	for _, c := range cases {
+		if got := a.hasMention(c.text); got != c.want {
+			t.Errorf("%s: hasMention(%q) = %v, want %v", c.name, c.text, got, c.want)
+		}
+	}
+
+	// Dedicated trailing-dot adapter.
+	b := &mattermostAdapter{botUsername: "ops1."}
+	if !b.hasMention("@ops1. hello") {
+		t.Error("hasMention must match a username ending in '.'")
+	}
+	if b.hasMention("@ops1.xyz hello") {
+		t.Error("hasMention must NOT fire when '.' is a prefix of a longer username")
+	}
+}
+
+// #963 regression: bot name "al" must not fire on "@alex".
+func TestIssue4322ShortNameGuardPreserved(t *testing.T) {
+	a := &mattermostAdapter{botUsername: "al"}
+
+	if a.hasMention("@alex hello") {
+		t.Error("short name 'al' must not match '@alex' (#963)")
+	}
+	if !a.hasMention("@al hello") {
+		t.Error("'@al' alone must match")
+	}
+	if a.hasMention("@alice.") {
+		t.Error("'@alice.' must not match bot 'al' (continuation bytes)")
+	}
+}
+
+func TestIssue4322StripMention(t *testing.T) {
+	a := &mattermostAdapter{botUsername: "dev-", botUserID: "abc123"}
+
+	cases := []struct {
+		name string
+		text string
+		want string
+	}{
+		{"trailing dash stripped", "@dev- 帮我看下日志", "帮我看下日志"},
+		{"uppercase mention stripped, body case kept", "@DEV- Keep This", "Keep This"},
+		{"user id stripped", "@abc123 ping me", "ping me"},
+		{"longer username not carved (#963)", "@alex is here", "@alex is here"},
+		{"no mention untouched", "plain text", "plain text"},
+		// Double space is pre-existing semantics (old regex left it too);
+		// only the mention itself is removed mid-text.
+		{"mid-text mention stripped", "hey @dev- check this", "hey  check this"},
+	}
+
+	for _, c := range cases {
+		if got := a.stripMention(c.text); got != c.want {
+			t.Errorf("%s: stripMention(%q) = %q, want %q", c.name, c.text, got, c.want)
+		}
+	}
+}