fix: flutter analyze Warnings beheben (totes/unerreichbares Code)

Entfernt tatsächlich toten Code, den flutter analyze als Warning markiert
hatte: unbenutzte Felder/Parameter (_saved, _hovered wird jetzt für Hover-
Feedback genutzt, destructive-Flag ohne Aufrufer, size-Parameter ohne
Override), unerreichbaren dead_code (Room.topic/Space.topic sind laut SDK
nie null, client.database ist nie null) sowie Legacy-Funktionen aus der
alten Push-Architektur (_showNotif/_fetchTitle, ersetzt durch natives
PushService.kt) und einen leeren Noise-Suppression-Stub ohne Aufrufer.
Keine funktionale Verhaltensänderung an aktiven Code-Pfaden.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

lib/widgets/create_join_dialog.dart

@@ -518,13 +518,12 @@ class _SpaceEditDialogState extends ConsumerState<SpaceEditDialog> {
   late TextEditingController _topicCtrl;
   bool _saving = false;
   String? _error;
-  bool _saved = false;
 
   @override
   void initState() {
     super.initState();
     _nameCtrl = TextEditingController(text: widget.space.getLocalizedDisplayname());
-    _topicCtrl = TextEditingController(text: widget.space.topic ?? '');
+    _topicCtrl = TextEditingController(text: widget.space.topic);
   }
 
   @override
@@ -535,17 +534,17 @@ class _SpaceEditDialogState extends ConsumerState<SpaceEditDialog> {
   }
 
   Future<void> _save() async {
-    setState(() { _saving = true; _error = null; _saved = false; });
+    setState(() { _saving = true; _error = null; });
     try {
       final name = _nameCtrl.text.trim();
       final topic = _topicCtrl.text.trim();
       if (name.isNotEmpty && name != widget.space.getLocalizedDisplayname()) {
         await widget.space.setName(name);
       }
-      if (topic != (widget.space.topic ?? '')) {
+      if (topic != widget.space.topic) {
         await widget.space.setDescription(topic);
       }
-      if (mounted) setState(() { _saving = false; _saved = true; });
+      if (mounted) setState(() { _saving = false; });
       await Future.delayed(const Duration(seconds: 1));
       if (mounted) Navigator.of(context).pop(true);
     } catch (e) {
@@ -674,7 +673,7 @@ class _RoomSettingsDialogState extends ConsumerState<RoomSettingsDialog> {
   void initState() {
     super.initState();
     _nameCtrl = TextEditingController(text: widget.room.getLocalizedDisplayname());
-    _topicCtrl = TextEditingController(text: widget.room.topic ?? '');
+    _topicCtrl = TextEditingController(text: widget.room.topic);
   }
 
   @override
@@ -691,7 +690,7 @@ class _RoomSettingsDialogState extends ConsumerState<RoomSettingsDialog> {
         await widget.room.setName(_nameCtrl.text.trim());
       }
       final newTopic = _topicCtrl.text.trim();
-      if (newTopic != (widget.room.topic ?? '')) {
+      if (newTopic != widget.room.topic) {
         await widget.room.setDescription(newTopic);
       }
       if (mounted) Navigator.of(context).pop();

lib/widgets/pyramid_loader.dart

@@ -127,17 +127,6 @@ class _PyramidPainter extends CustomPainter {
   Offset _proj(List<double> v, double sc, double cx, double cy, double tr) =>
       Offset(cx + v[0] * sc, cy + (v[1] * cos(tr) + v[2] * sin(tr)) * sc);
 
-  double _frontness(List<List<double>> verts) {
-    final a = verts[0], b = verts[1], c = verts[2];
-    final ux = b[0]-a[0], uy = b[1]-a[1], uz = b[2]-a[2];
-    final vx = c[0]-a[0], vy = c[1]-a[1], vz = c[2]-a[2];
-    final nz = ux * vy - uy * vx;
-    final nLen = sqrt(
-      pow(uy * vz - uz * vy, 2) + pow(uz * vx - ux * vz, 2) + nz * nz,
-    );
-    return nLen == 0 ? 0 : max(0.0, -nz / nLen);
-  }
-
   Color _darken(Color c, double amount) => Color.fromARGB(
     c.alpha,
     max(0, (c.red   * (1 - amount)).round()),

lib/widgets/screen_share_picker.dart

@@ -1,4 +1,3 @@
-import 'dart:typed_data';
 import 'package:flutter/material.dart';
 import 'package:flutter_webrtc/flutter_webrtc.dart';
 import 'package:pyramid/core/theme.dart';

lib/widgets/settings_modal.dart

@@ -859,7 +859,6 @@ class _PrimaryBtn extends StatelessWidget {
   final VoidCallback? onPressed;
   final PyramidTheme pt;
   final bool loading;
-  final bool destructive;
 
   const _PrimaryBtn({
     required this.label,
@@ -867,13 +866,12 @@ class _PrimaryBtn extends StatelessWidget {
     this.icon,
     this.onPressed,
     this.loading = false,
-    this.destructive = false,
   });
 
   @override
   Widget build(BuildContext context) {
-    final bg = destructive ? pt.danger : pt.accent;
-    final fg = destructive ? Colors.white : pt.accentFg;
+    final bg = pt.accent;
+    final fg = pt.accentFg;
     return ElevatedButton.icon(
       style: ElevatedButton.styleFrom(
         backgroundColor: bg,
@@ -3626,7 +3624,6 @@ class _EncryptionSectionState extends ConsumerState<_EncryptionSection> {
     try {
       final client = await ref.read(matrixClientProvider.future);
       final db = client.database;
-      if (db == null) throw Exception('Datenbank nicht verfügbar.');
 
       final stored = await db.getAllInboundGroupSessions();
       final sessions = <Map<String, dynamic>>[];