fix: implement chat mode tools filtering and session marker cleanup

Chat mode now properly limits tools to: file_operations, memory_operations,
web_operations, todo_operations, interact (tools 1, 4, 5, 6, 8).

Changes:
- SimpleAIAgent: added todo_operations to chat_mode_tools list
- PromptBuilder: fixed caching logic - cache now only used when no enable_tools
  filter is set. Previously filtering was applied but cached result returned
  anyway, causing all 11 tools to still appear.
- Chat.pm: strip session markers from final_response before displaying.
  Both code paths (messages_saved_during_workflow and else branch) now
  clean the marker before add_to_buffer.
- StreamingController: strip simple session marker format (<!--session:name-->)
  in addition to structured format (<!--session:{...}-->) in all buffer flush
  locations. Previously only structured format was stripped, leaving simple
  markers visible in output.

Testing: --chat mode now shows only 5 tools and no session data in output.

Author: fewtarius

lib/CLIO/Core/PromptBuilder.pm

@@ -166,9 +166,10 @@ sub generate_tools_section {
     my ($self) = @_;
 
     # Cache the tools section since tool registrations don't change during a session
-    # But don't cache if there's an enable_tools filter (varies per session in multi-agent scenarios)
-    my $cache_key = $self->{enable_tools} ? '_filtered_' . $self->{enable_tools} : '';
-    return $self->{_tools_section_cache} if $self->{_tools_section_cache} && !$cache_key;
+    # Only use cache if there's no enable_tools filter (which varies per session)
+    if (!$self->{enable_tools} && $self->{_tools_section_cache}) {
+        return $self->{_tools_section_cache};
+    }
 
     # Get all registered tool OBJECTS (not just names)
     my $all_tools = $self->{tool_registry}->get_all_tools();

lib/CLIO/Core/SimpleAIAgent.pm

@@ -44,7 +44,7 @@ sub new {
     bless $self, $class;
 
     # Chat mode: default to limited tool set and chat system prompt
-    my $chat_mode_tools = 'web_operations,file_operations,memory_operations,interact';
+    my $chat_mode_tools = 'web_operations,file_operations,memory_operations,interact,todo_operations';
     my $chat_mode_prompt = 'chat';
 
     # Apply chat mode defaults if enabled (but respect explicit --enable/--prompt overrides)

lib/CLIO/UI/Chat.pm

@@ -765,17 +765,24 @@ sub _handle_ai_response {
     }
 
     if ($accumulated_content) {
-        $accumulated_content =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;
+        $accumulated_content =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $accumulated_content =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
     }
 
     if ($result && $result->{messages_saved_during_workflow}) {
         log_debug('Chat', "Skipping session save - messages already saved during workflow");
-        $self->add_to_buffer('assistant', $result->{final_response} // '') if $result->{final_response};
+        my $display_response = $result->{final_response} // '';
+        $display_response =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $display_response =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
+        $self->add_to_buffer('assistant', $display_response) if $display_response;
     } elsif ($result && $result->{final_response}) {
         log_debug('Chat', "Storing final_response in session (length=" . length($result->{final_response}) . ")");
         my $sanitized = sanitize_text($result->{final_response});
         $self->{session}->add_message('assistant', $sanitized);
-        $self->add_to_buffer('assistant', $result->{final_response});
+        my $display_response = $result->{final_response};
+        $display_response =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $display_response =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
+        $self->add_to_buffer('assistant', $display_response);
     } elsif ($accumulated_content) {
         log_debug('Chat', "Storing accumulated_content in session (length=" . length($accumulated_content) . ")");
         my $sanitized = sanitize_text($accumulated_content);

lib/CLIO/UI/StreamingController.pm

@@ -238,7 +238,8 @@ sub flush {
 
     # Flush markdown buffer
     if ($self->{markdown_buffer} =~ /\S/) {
-        $self->{markdown_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;
+        $self->{markdown_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $self->{markdown_buffer} =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
     }
     if ($self->{markdown_buffer} =~ /\S/) {
         log_debug('Chat', "Flushing markdown_buffer (" . length($self->{markdown_buffer}) . " bytes)");
@@ -256,7 +257,8 @@ sub flush {
 
     # Flush line buffer (incomplete final line)
     if ($self->{line_buffer} =~ /\S/) {
-        $self->{line_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;
+        $self->{line_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $self->{line_buffer} =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
     }
     if ($self->{line_buffer} =~ /\S/) {
         log_debug('Chat', "Flushing line_buffer (" . length($self->{line_buffer}) . " bytes)");
@@ -291,6 +293,8 @@ sub flush_for_tools {
     my $printed = 0;
 
     if ($self->{markdown_buffer} =~ /\S/) {
+        $self->{markdown_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $self->{markdown_buffer} =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
         my $output = $self->{markdown_buffer};
         if ($ui->{enable_markdown}) {
             $output = $ui->render_markdown($self->{markdown_buffer});
@@ -304,7 +308,8 @@ sub flush_for_tools {
     }
 
     if ($self->{line_buffer} =~ /\S/) {
-        $self->{line_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;
+        $self->{line_buffer} =~ s/\s*<!--session:\{[^}]*\}-->\s*//sg;  # Structured
+        $self->{line_buffer} =~ s/\s*<!--session:[a-z][a-z0-9_-]{2,50}-->\s*//sgi;  # Simple
     }
     if ($self->{line_buffer} =~ /\S/) {
         my $output = $self->{line_buffer};