Add logcat log collection for Android debug bundles

Move log collection into platform-dispatched addPlatformLog():
- Android: dumps logcat buffer via /system/bin/logcat -d
- Other platforms: existing file-based log + systemd fallback

client/internal/debug/debug_android.go

@@ -0,0 +1,34 @@
+//go:build android
+
+package debug
+
+import (
+	"fmt"
+	"os/exec"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func (g *BundleGenerator) addPlatformLog() error {
+	cmd := exec.Command("/system/bin/logcat", "-d")
+	out, err := cmd.Output()
+	if err != nil {
+		return fmt.Errorf("run logcat: %w", err)
+	}
+
+	var logReader *strings.Reader
+	if g.anonymize {
+		anonymized := g.anonymizer.AnonymizeString(string(out))
+		logReader = strings.NewReader(anonymized)
+	} else {
+		logReader = strings.NewReader(string(out))
+	}
+
+	if err := g.addFileToZip(logReader, "logcat.txt"); err != nil {
+		return fmt.Errorf("add logcat to zip: %w", err)
+	}
+
+	log.Debugf("added logcat output to debug bundle (%d bytes)", len(out))
+	return nil
+}