diff --git a/lib/core/services/api_service.dart b/lib/core/services/api_service.dart
index 45c59f0..014f51e 100644
--- a/lib/core/services/api_service.dart
+++ b/lib/core/services/api_service.dart
@@ -14,9 +14,7 @@ import '../models/chat_message.dart';
 import '../auth/api_auth_interceptor.dart';
 import '../validation/validation_interceptor.dart';
 import '../error/api_error_interceptor.dart';
-import 'sse_parser.dart';
 // Tool-call details are parsed in the UI layer to render collapsible blocks
-import 'stream_recovery_service.dart';
 import 'persistent_streaming_service.dart';
 import '../utils/debug_logger.dart';
 
@@ -2784,12 +2782,6 @@ class ApiService {
           if (!streamController.isClosed) streamController.close();
         }
       }();
-    } else {
-      // Ensure we do not leak background-only identifiers into SSE path
-      data.remove('session_id');
-      data.remove('id');
-      // Use SSE streaming with proper parser (chat_id allowed)
-      _streamSSE(data, streamController, messageId);
     }
 
     return (
@@ -3032,9 +3024,8 @@ class ApiService {
       }
     } catch (_) {}
   }
-
-  // SSE streaming with persistent background support - Main Implementation
-  void _streamSSE(
+  // SSE helpers removed: background task flow is the only path now.
+  /* void _streamSSE(
     Map<String, dynamic> data,
     StreamController<String> streamController,
     String messageId,
@@ -3690,6 +3681,7 @@ class ApiService {
     }
   }
 
+  */
   // Legacy Socket.IO and older SSE methods removed
 
   // File upload for RAG
diff --git a/lib/core/services/share_receiver_service.dart b/lib/core/services/share_receiver_service.dart
index 93838ba..d7d0375 100644
--- a/lib/core/services/share_receiver_service.dart
+++ b/lib/core/services/share_receiver_service.dart
@@ -50,9 +50,9 @@ final shareReceiverInitializerProvider = Provider<void>((ref) {
   // React when auth/model changes to process a queued share
   ref.listen<AuthNavigationState>(
     authNavigationStateProvider,
-    (_, __) => maybeProcessPending(),
+    (prev, next) => maybeProcessPending(),
   );
-  ref.listen(selectedModelProvider, (_, __) => maybeProcessPending());
+  ref.listen(selectedModelProvider, (prev, next) => maybeProcessPending());
   // Also poll once shortly after navigation settles to ensure ChatPage is ready
   Future.delayed(const Duration(milliseconds: 150), () => maybeProcessPending());
 
diff --git a/lib/core/utils/reasoning_parser.dart b/lib/core/utils/reasoning_parser.dart
index e670f57..17fa311 100644
--- a/lib/core/utils/reasoning_parser.dart
+++ b/lib/core/utils/reasoning_parser.dart
@@ -1,7 +1,7 @@
-/// Utility class for parsing and extracting reasoning/thinking content from messages
+/// Utility class for parsing and extracting reasoning/thinking content from messages.
 class ReasoningParser {
-  /// Default tag pairs to detect raw reasoning blocks when providers don't emit <details>
-  /// This mirrors Open WebUI defaults: <think>...</think>, <reasoning>...</reasoning>
+  /// Default tag pairs to detect raw reasoning blocks when providers don't emit `<details>`.
+  /// This mirrors Open WebUI defaults: `<think>...</think>`, `<reasoning>...</reasoning>`.
   static const List<List<String>> defaultReasoningTagPairs = <List<String>>[
     ['<think>', '</think>'],
     ['<reasoning>', '</reasoning>'],
@@ -9,8 +9,8 @@ class ReasoningParser {
 
   /// Parses a message and extracts reasoning content
   /// Supports:
-  /// - <details type="reasoning" ...> blocks (server-emitted)
-  /// - Raw tag pairs like <think>...</think> or <reasoning>...</reasoning>
+  /// - `<details type="reasoning" ...>` blocks (server-emitted)
+  /// - Raw tag pairs like `<think>...</think>` or `<reasoning>...</reasoning>`
   /// - Optional custom tag pair override
   static ReasoningContent? parseReasoningContent(
     String content, {
@@ -19,7 +19,7 @@ class ReasoningParser {
   }) {
     if (content.isEmpty) return null;
 
-    // 1) Prefer server-emitted <details type="reasoning"> blocks
+    // 1) Prefer server-emitted `<details type="reasoning">` blocks
     final detailsRegex = RegExp(
       r'<details\s+type="reasoning"(?:\s+done="(true|false)")?(?:\s+duration="(\d+)")?[^>]*>\s*<summary>([^<]*)<\/summary>\s*([\s\S]*?)<\/details>',
       multiLine: true,
@@ -44,7 +44,7 @@ class ReasoningParser {
       );
     }
 
-    // 2) Handle partially streamed <details> (opening present, no closing yet)
+    // 2) Handle partially streamed `<details>` (opening present, no closing yet)
     final openingIdx = content.indexOf('<details type="reasoning"');
     if (openingIdx >= 0 && !content.contains('</details>')) {
       final after = content.substring(openingIdx);
@@ -80,7 +80,7 @@ class ReasoningParser {
     for (final pair in tagPairs) {
       final start = RegExp.escape(pair[0]);
       final end = RegExp.escape(pair[1]);
-      final tagRegex = RegExp('($start)([\n\r\s\S]*?)($end)', multiLine: true, dotAll: true);
+      final tagRegex = RegExp('($start)([\s\S]*?)($end)', multiLine: true, dotAll: true);
       final match = tagRegex.firstMatch(content);
       if (match != null) {
         final reasoning = (match.group(2) ?? '').trim();
diff --git a/lib/core/utils/tool_calls_parser.dart b/lib/core/utils/tool_calls_parser.dart
index f000733..d6e7bee 100644
--- a/lib/core/utils/tool_calls_parser.dart
+++ b/lib/core/utils/tool_calls_parser.dart
@@ -32,7 +32,7 @@ class ToolCallsContent {
   });
 }
 
-/// Utility to parse <details type="tool_calls"> blocks from content
+/// Utility to parse `<details type="tool_calls">` blocks from content.
 class ToolCallsParser {
   static String _unescapeHtml(String s) {
     return s
@@ -135,7 +135,7 @@ class ToolCallsParser {
               done: done,
               arguments: args,
               result: result,
-              files: (files is List) ? files as List : null,
+              files: (files is List) ? files : null,
             ),
           ),
         );
@@ -230,10 +230,10 @@ class ToolCallsParser {
     if (value == null) return '';
     try {
       final pretty = const JsonEncoder.withIndent('  ').convert(value);
-      return pretty.length > max ? pretty.substring(0, max) + '\n…' : pretty;
+      return pretty.length > max ? '${pretty.substring(0, max)}\n…' : pretty;
     } catch (_) {
       final raw = value.toString();
-      return raw.length > max ? raw.substring(0, max) + '…' : raw;
+      return raw.length > max ? '${raw.substring(0, max)}…' : raw;
     }
   }
 }
diff --git a/lib/features/chat/providers/chat_providers.dart b/lib/features/chat/providers/chat_providers.dart
index 8a8fcba..c498031 100644
--- a/lib/features/chat/providers/chat_providers.dart
+++ b/lib/features/chat/providers/chat_providers.dart
@@ -1219,7 +1219,7 @@ Future<void> _sendMessageInternal(
                     if (apiSvc != null && chatId != null && chatId.isNotEmpty) {
                       Future.microtask(() async {
                         try {
-                          final resp = await apiSvc.dio.get('/api/v1/chats/' + chatId);
+                          final resp = await apiSvc.dio.get('/api/v1/chats/$chatId');
                           final data = resp.data as Map<String, dynamic>;
                           String content = '';
                           final chatObj = data['chat'] as Map<String, dynamic>?;
@@ -1305,7 +1305,7 @@ Future<void> _sendMessageInternal(
                 try {
                   if (line is String) {
                     final s = line.trim();
-                    DebugLogger.stream('Socket [' + channel + '] line=' + (s.length > 160 ? s.substring(0, 160) + '…' : s));
+                    DebugLogger.stream('Socket [$channel] line=${s.length > 160 ? '${s.substring(0, 160)}…' : s}');
                     if (s == '[DONE]' || s == 'DONE') {
                       socketService.offEvent(channel);
                       // Channel completed
@@ -1350,13 +1350,13 @@ Future<void> _sendMessageInternal(
                             if (delta.containsKey('content')) {
                               final c = delta['content']?.toString() ?? '';
                               if (c.isNotEmpty) {
-                                DebugLogger.stream('Socket [' + channel + '] delta.content len=' + c.length.toString());
+                                DebugLogger.stream('Socket [$channel] delta.content len=${c.length}');
                               }
                             }
                             // Surface tool_calls status
                             if (delta.containsKey('tool_calls')) {
                               if (kSocketVerboseLogging) {
-                                DebugLogger.stream('Socket [' + channel + '] delta.tool_calls detected');
+                                DebugLogger.stream('Socket [$channel] delta.tool_calls detected');
                               }
                               final tc = delta['tool_calls'];
                               if (tc is List) {
@@ -1431,7 +1431,7 @@ Future<void> _sendMessageInternal(
             // Show an executing tile immediately using provided tool info
             try {
               final name = payload['name']?.toString() ?? 'tool';
-              DebugLogger.stream('Socket execute:tool name=' + name);
+              DebugLogger.stream('Socket execute:tool name=$name');
               final status = '\n<details type="tool_calls" done="false" name="$name"><summary>Executing...</summary>\n</details>\n';
               ref.read(chatMessagesProvider.notifier).appendToLastMessage(status);
             } catch (_) {}
@@ -1447,7 +1447,7 @@ Future<void> _sendMessageInternal(
           if (data == null) return;
           final type = data['type'];
           final payload = data['data'];
-          DebugLogger.stream('Socket channel-events: type=' + type.toString());
+          DebugLogger.stream('Socket channel-events: type=$type');
           // Handle generic channel progress messages if needed
           if (type == 'message' && payload is Map) {
             final content = payload['content']?.toString() ?? '';
diff --git a/lib/features/chat/widgets/assistant_message_widget.dart b/lib/features/chat/widgets/assistant_message_widget.dart
index e90a0e7..72372f2 100644
--- a/lib/features/chat/widgets/assistant_message_widget.dart
+++ b/lib/features/chat/widgets/assistant_message_widget.dart
@@ -198,10 +198,10 @@ class _AssistantMessageWidgetState extends ConsumerState<AssistantMessageWidget>
     String _pretty(dynamic v, {int max = 1200}) {
       try {
         final pretty = const JsonEncoder.withIndent('  ').convert(v);
-        return pretty.length > max ? pretty.substring(0, max) + '\n…' : pretty;
+        return pretty.length > max ? '${pretty.substring(0, max)}\n…' : pretty;
       } catch (_) {
         final s = v?.toString() ?? '';
-        return s.length > max ? s.substring(0, max) + '…' : s;
+        return s.length > max ? '${s.substring(0, max)}…' : s;
       }
     }
 
diff --git a/lib/features/chat/widgets/modern_chat_input.dart b/lib/features/chat/widgets/modern_chat_input.dart
index b2ac0a9..d6782e1 100644
--- a/lib/features/chat/widgets/modern_chat_input.dart
+++ b/lib/features/chat/widgets/modern_chat_input.dart
@@ -1164,11 +1164,9 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
       _textSub?.cancel();
       _textSub = stream.listen(
         (text) async {
-          final updated =
-              (_baseTextAtStart.isEmpty
-                  ? ''
-                  : (_baseTextAtStart.trimRight() + ' ')) +
-              text;
+          final updated = _baseTextAtStart.isEmpty
+              ? text
+              : '${_baseTextAtStart.trimRight()} $text';
           _controller.value = TextEditingValue(
             text: updated,
             selection: TextSelection.collapsed(offset: updated.length),
diff --git a/lib/shared/services/tasks/task_queue.dart b/lib/shared/services/tasks/task_queue.dart
index e740458..8da9cbc 100644
--- a/lib/shared/services/tasks/task_queue.dart
+++ b/lib/shared/services/tasks/task_queue.dart
@@ -25,7 +25,7 @@ class TaskQueueNotifier extends StateNotifier<List<OutboundTask>> {
 
   bool _processing = false;
   final Set<String> _activeThreads = <String>{};
-  int _maxParallel = 2; // bounded parallelism across conversations
+  final int _maxParallel = 2; // bounded parallelism across conversations
 
   Future<void> _load() async {
     try {